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The Cambridge Manuals of Science and
Literature
THE INDIVIDUAL IN THE
ANIMAL KINGDOM
CAMBRIDGE UNIVERSITY PRESS
FETTER LANE, E.G.
C. F. CLAY, MANAGER
100, PRINCES STREET
ILontron: H. K. LEWIS, 136, GOWER STREET, W.C.
WILLIAM WESLEY AND SON, 28, ESSEX STREET, STRAND
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All rights reserved
Volvox globator Ehrenberg. An adult asexual colony, highly magni-
fied. The hexagonal areas represent the gelatinous coats of the
individual cells in surface view. The thin common envelope of
the whole colony is seen round the circumference. In the hinder
half of the colony are seen two of the large asexual reproductive
cells, and various stages of their development into daughter-
colonies. The two most advanced daughter-colonies have already
secreted a common envelope of their own. (After A. Lang.)
THE INDIVIDUAL
IN THE
ANIMAL KINGDOM
JULIAN S. HUXLEY, B.A.
Research Associate of the Rice Institute,
Houston, Texas
Late Lecturer of Balliol
College, Oxford
Cambridge :
the University Press
1912
Cambridge :
PRINTED BY JOHN CLAY, M.A.
AT THE UNIVERSITY PRESS
With the exception of the coat of arms at
the foot, the design on the title page is a
reproduction of one used by the earliest known
Cambridge printer, John Siberch, 1521
PREFACE
I MUST confess that when I made choice of Animal
Individuality as my subject, I had no idea of its
real importance, its vastness and many ramifications :
the teaching of philosophical biology is in England
to-day somewhat of a Cinderella. The working out
of the concept, full of interest as it was, brought also
regret ; a book of the size could have been — should
have been — made from every twig and a stout octavo
from the central trunk. This might not be ; and the
unavoidable compression must be pardoned. The
general reader must imitate the Organic Individual
(p. 26) and take unto himself wings of thought and
conscious effort to skip across the unbridged gaps
that perforce remain ; with them to aid, I think he
will find the stepping-stones not too far apart. The
professed biologist must not cavil when he finds
some merely general truth set dogmatically down
as universal; in biology (still so empirical and ten-
tative) there are always exceptions to the poor
partial "Laws" we can formulate to-day. To have
qualified every statement that needed qualification
would have added much to the book's bulk without
aiding the argument or being really more " scientific."
My indebtednesses are great. It will easily be
seen how much I owe to M. Bergson, who, whether
one agrees or no with his views, has given a stimulus
(most valuable gift of all) to Biology and Philosophy
viii PREFACE
alike. The various Oxford philosopher-friends who
have helped to comb out the tangles of a zoologist's
mind know how grateful I am to them: I will not
name them here for fear my heresies be laid to their
charge.
Certain criticisms have convinced me that some
explanation of the scope of this book will here not
be out of place. The task I have attempted in the
following pages is a two-fold one. First, I have tried
to frame a general definition of the Individual,
sufficiently objective to permit of its application by
the man of science, while at the same time admitted
as accurate (though perhaps regarded as incomplete )
by the philosopher. Secondly, I have tried to show
in what ways Individuality, as thus defined //// ///<•.
manifests itself in the Animal Kingdom.
I wish here to point out in general, that the
failure of one of these aims does not preclude the
success of the other ; and, in particular, this : — it is
possible that the philosophically-minded will quarrel
with my definition of the Individual (p. 28) as a
"continuing whole with inter-dependent parts" (to
put it at its baldest). But even if he denies that
the definition applies to the Individual, he must. I
think, admit that it does apply to something, and to
something which plays a very important part in the
organic world. He will, I believe, after reading the
subsequent chapters, be brought to see that every
living thing is in some way related to one of these
PREFACE ix
systems, these continuing wholes ; and that such
wholes, though they may not in his eyes deserve the
name of Individual, are yet sufficiently widespread
and important to merit some title of their own.
Put in other words, the major portion of this
book is devoted to showing that living matter always
tends to group itself into these " closed, independent
>v<tems with harmonious parts." Though the closure
is never complete, the independence never absolute,
the harmony never perfect, yet systems and tendency
alike have real existence. Such systems I personally
believe can be identified with the Individuals treated
of by the philosopher, and I have tried to establish
this belief. But what's in a name ? the systems are
tlnri ir],<itf ,*(,' »•< may choose to call them, and if
I have shown that. I shall be content.
In conclusion. I will only hope that this little
book may help, however slightly, to decrease still
further the gap (to-day happily lessening) between
Science, Philosophy, and the ideas and interests of
evervdav life.
J. S. HUXLEY.
BALLIOL COLLEGE,
OXFORD.
Sept., 1912.
The numbers in brackets to be found in the text refer to the
Bibliography at the end of the book.
An Appendix has also been added, giYing some of the main con-
clusions in tabular form.
CONTENTS
CHAP. PAGE
I. The Idea of Individuality 1
II. The Biological Foundations of Individuality . . 31
III. Some Other Definitions of Animal Individuality . 66
IV. The Second Grade of Individuality and its Attainment 85
V. The Later Progress of Individuality . . . 114
VI. The Relation of Individuality to Matter: Conclusion 144
Literature cited 155
Appendix A 157
Appendix B . .159
Index 162
LIST OF ILLUSTRATIONS
Volvox globator Ehrenberg . . . Frontispiece
FIG. PAGE
1. Diagram of the life-history of the Liver-fluke . . 22
2. Portion of colony of Bougainmllea fruticosa . . 37
3. Hydra 39
4. Stylonychia my til us . . . . . . . 41
5. Pilidium with young Nemertine enclosed . . 73
6. Clathrina coriacea, histology 91
7. Gonium 103
8. Haplozoon macrostylum 108
9. Probable evolution of the Catenata . . . .111
10. Part of a colony of Hydr actinia . . . .117
11. Diphyes campanulata 121
12. Physcia parietina 123
13. The Yucca and its Moth 129
14. Development of a nerve- cell 139
15. Regeneration in Planaria lugubris . . . .145
16. Elementary Structure in plants 159
Figs. 2, 10, and 11 are reproduced from the Encyclopaedia
Britannica (eleventh edition) ; figs. 6 and 12 are from
Lankester's Treatise on Zoology, Vol. n, and Scott's Struc-
tural Botany respectively, by kind permission of Messrs
A. & C. Black ; fig. 7 is from West's British Freshwater
Algae (Camb. Univ. Press) ; and fig. 13 is from Weismann's
Evolution Theory, by permission of Mr Edward Arnold.
CHAPTER I .
THE IDEA OF INDIVIDUALITY
"Die Zeit ist abgeflossen, wo mir noch Zufalle begegnen durften;
und was konnte jetzt noch zu mir fallen, was nicht schon mein Eigen
ware ! " NIETZSCHE.
"La vie manifesto une recherche de 1'individualite et tend a
constituer des systemes naturellement isoles, naturellement clos."
BERGSON.
"ACCIDENTS cannot happen to me." So says
Nietzsche's Zarathustra, and in the saying proclaims
to the world the perfection of his individuality. It
might be thought that such a being was far outside
the purview of the Zoologist, that he himself belonged
to imagination and his individuality to the most
speculative philosophy, and that both he and it
should be left where they belong, where they could
not contaminate the "pure objective truth of science."
That I think is an error: for the idea of
individuality is dealt with of necessity both by
Science and by Philosophy, and in such a difficult
subject it would be mistaken to reject any sources of
help. Not only that, but animal individuality with
H. 1
2 ANIMAL INDIVIDUALITY [CH.
the advent of consciousness, though still remaining a
lawful subject of the Zoologist, becomes naturalised
in the proper realms of the Psychologist and the
Philosopher and transfers thither the major portion
of its business.
More, even were the Zoologist to confine himself
to a description of non-conscious organic individuals
and the deductions he drew from them, he would
often find himself without a reasoned criterion of
Individuality or a true idea of what he means by
" higher " or " lower " individualities. It is only when
the Biologist and the Philosopher join hands that
they can begin to see the subject in its entirety.
There are two chief ways of enquiry into the
meaning of things — the static and the dynamic. In
determining the nature of Individuality, for instance,
we may seek to define it by comparing the different
objects we are agreed upon to call individuals and
then taking their Highest Common Measure — ex-
tracting from them the utmost which is common to
all and erecting that as the minimum conception of
Individuality ; or we may search for the movement
of individuality through the individuals, and, finding
that some are more perfect, some more rudimentary
in their individuality, thus establish a direction in
which its movement is tending, and from that deduce
the properties of the Perfect Individual, possessing
then a maximum conception of Individuality.
i] IDEA OF INDIVIDUALITY 3
In view of the change, the progressive change or
evolution which is one of the fundamental things of
Life, the second method is the more natural, and in
a way includes the first. Using it in the main,
therefore, but not rejecting the other as an engine,
we will begin to lay siege to the notion of in-
dividuality ; and so, having justified the necessity
for some philosophical view of the subject, but with
apologies none the less for a biologist's intrusion on
another's domain, we return to Zarathustra and his
pronouncement.
" Accidents do not happen to me." — When a glance
is thrown over the various forms of animal life to
which the name of Individual is naturally conceded1,
it is seen that in spite of many side-ventures, they
can be arranged in a single main series in which
certain characters are manifested more clearly and
more thoroughly at the top than at the bottom. One
of these characters is independence of the outer
1 There may appear to be a vicious circle in the use of the word
individual before we know its definition; in reality there is not.
The word individual has not been manufactured to label a theoretical
concept, but to denote something existing. It was originally applied
to human beings, and a special word had to be used for them because
it was felt that they differed in certain important ways from mere
things. Certain other objects (all of them organic, but together
making only a portion of the whole organic world) are immediately
recognized as possessing similar attributes, and it is obvious that
they too must be Individuals, although equally obvious that we have
only used, without defining, the category " Individual."
1—2
4 ANIMAL INDIVIDUALITY [OH.
world and all its influences — in other words, immunity
from accidents. By independence is not meant the
independence of the recluse or the ascetic, but that
other independence belonging to the great man of
action and the inventor. .These are not independent
in the most literal sense — they do not "do without,"
they are not proud of existing on the barest minimum ;
the ultimate logical end of that kind of independence
is atrophy, both mental and physical. Their other,
higher independence involves this much of dependence,
that they employ the things of the external world as
material with which to work. For the making of
bricks, you are dependent upon straw : but you
attain a higher independence by making bricks and
being dependent upon straw than by being in-
dependent of straw and lacking bricks. They gain
their independence by using the outer world for
their own ends, harnessing some of its forces to
strive with and overcome the rest. At the least
they can resist the adverse current, displaying
a purpose of their own which is not whirled away
by every wind of fate. "Accidents cannot happen
to me " — so spake Zarathustra, and then added this
reason : " Because all that could now happen to me
would be my own."
In this making of Nature his own, civilized man
has an individuality vastly fuller, more perfect, than
the savage. Both in resisting adverse forces and in
i] IDEA OF INDIVIDUALITY 5
harnessing the indifferent to his will, he is far
superior ; take as a concrete instance, for one the
stamping out of malaria in the Suez Canal zone,
and for the other the invention of the microscope.
At the other end of the series, even the simplest
Protozoan has something of the same power. Al-
though in a current against which the savage (let
alone the steamboat of the civilised man) could
easily swim, the Protozoan is carried utterly away,
yet none the less it has some power of independent
movement, and is not helpless like the inorganic
grain of dust.
This gradual increase of independence up from
the Protozoa to the highest animals is due partly to
mere increase of size1 : the same current that carries
the grain of sand in its midst and rolls the pebble on
its bed, swirls powerless past the boulder.
Partly it is due to increased complexity : the
actions of the caterpillar who once in his life weaves
an elaborate cradle to support his transmuted pupa-
self, without either practice or the sight of another to
teach him, can only be due to the actual machinery
of his brain, working in a way almost as stereotyped
as our machines, — a long series of ready- wound clock-
work which must unwind itself when a certain catch
is released. The Protozoan or the Jelly-fish is not
capable of such precise and ordered action because it
1 See pp. 85— 8Q for some further treatment of the value of size.
6 ANIMAL INDIVIDUALITY [CH.
has not the requisite machinery, the requisite com-
plication of brain and muscle.
Lastly it is due to increased adaptability, which
depends mainly upon increased power of choice.
Adaptability seems to be a property soon acquired
by a complex and unstable substance, or rather
mixture of substances, like protoplasm. Roux (16)
by extending Darwin's idea of Natural Selection or
survival of the fittest from individuals to the organs
and tissues, the cells and varieties of protoplasm within
the individual, has shown that some measure of
adaptability, or useful response to changed conditions,
becomes a common property of all living things.
This, though very important, has been slow in
action, merely automatic, and therefore limited in
its usefulness, the result, to speak in metaphors, not
of choice but of habit. What we call choice has only
become fully realized through a special arrangement
of special tissue — the brain.
Says Bergson : "A nervous system with neurones
placed end to end in such wise that, at the extremity
of each, manifold ways open in which manifold
questions present themselves, is a veritable reservoir
of indetermination " (1, p. 133). Such is the nervous
system of man : and whatever value we assign to the
idea of indetermination, whether we believe in the
reality of choice and free-will, or think that they are
only apparent, due to the relativity of our mental
i] IDEA OF INDIVIDUALITY 7
powers, the fact remains that in a brain which is
constructed after the pattern of our own, and in
which therefore we postulate the existence of Con-
sciousness, a new machinery, different in kind from
any machinery we have been able to construct, has
been introduced; machinery that by supplying the
individual with memory and reason gives him the
largest scope to adjust his actions, and so himself, to
the variations of circumstance.
Civilized man is the most independent, in our
sense, of any animal : this he owes partly to his com-
paratively large size, more to his purely mechanical
complexity of body and brain, giving him the pos-
sibility of many precise and separate actions, and
most to the unique machinery of part of his brain
which enables him to use his size and the smoothly-
working machine-actions of his body in the most
varied way.
But he is far from perfect independence of
accidents. A being to whom accidents really could
not happen might attain to that happy state through
having perfected himself in any of the three qualities
which have been seen to assist independence. By
incorporating more and more matter — that is, by
increasing in size — until co-extensive with the uni-
verse, he would obviously be entirely independent;
there would remain nothing on which to be dependent.
Since matter is what it is, man at least has little
8 ANIMAL INDIVIDUALITY [OH.
chance of advancing far along that road. By building
up within himself a separate machine for dealing with
each possible eventuality, independence would like-
wise be obtained were it not that there is an infinity of
eventualities, and so the project is self-contradictory.
But by perfecting his mental attributes — his means
of perceiving, remembering, and reasoning — he would
become capable of dealing with any one of the infinite
eventualities, for though he could not construct an
infinity of machines simultaneously, yet as each new
eventuality cropped up, he would be able to invent a
new plan to cope with it. Though Zarathustra had
climbed far up this path, he probably was not quite
accurate about the accidents : it is not likely that he
would be able to experience everything, to remember
everything, and to understand everything, but so alone
would he be altogether immune from the accidental.
That is neither here nor there. The chief importance
lies in this: all life of which we have any assured
cognizance is dependent upon or inseparably asso-
ciated with a certain kind of matter — protoplasm.
Knowing what we do of the properties of protoplasm,
it becomes evident that no considerable advance
towards independence through either of the first two
methods is physically possible for life ; it is only the
third way, with its multiplication of potentialities,
which, in spite of size really not so hugely great and
mechanism really not so vastly complex, can yet give
i] IDEA OF INDIVIDUALITY 9
life a considerable fresh amount of immunity from
accident.
The second quotation at the head of this chapter
seems at first sight to take a very different view of
the individual, conceiving of it as "a system naturally
isolated, naturally closed." By this Bergson means
that in any consideration of that system, it is the
unity of it as a whole that is important : more than
that, even if you want to consider a part of the
system by itself, you cannot do so, for it loses almost
all its significance when detached from the whole.
What is the meaning of the hand and its actions
apart from the functioning of the whole body? More
striking still, for here there are no physical con-
nections to sever, what is the meaning of a lonely
bee and its actions when it comes back to find its
hive destroyed? With inorganic things on the other
hand, a part does not lose significance when detached
from a system, nor the system appear less perfect for
the detachment of the part. The inorganic system is
a Particular, but not an Individual. Cause half a
mountain to be removed and cast into the sea : what
remains is still a mountain, though a different one.
Take away a planet, and the Solar System still works :
its working is different, but, as far as we can see, only
different, not less perfect.
Nietzsche's words affirmed the individual's prin-
ciple of action : Bergson's point out the inner unity
10 ANIMAL INDIVIDUALITY [OH.
for the good of which that action is performed. From
the latter we can deduce another attribute of in-
dividuality— its heterogeneity ; from that very unity
of the whole we can postulate diversity of its parts.
This sounds paradoxical, but in reality it can be easily
shown that nothing homogeneous can be an indi-
vidual.
Suppose (as is highly probable) that the earliest
forms of life were homogeneous in chemical compo-
sition. If so, even were they compelled by the
nature of things (see Chap. II) to exist as separate
masses of defined shape and size, even though, by
reason of their complicated atomic structure, they
could carry on all the diverse functions necessary for
their continued existence with their one chemical
substance, they would then not be individuals. There
is no unity residing in such masses — they are the
merest aggregates ; whether you divided one into two
or twenty or a hundred pieces it would still go on
working in the same way, without a break1, whereas
if you divide a man into two by cutting off his hand,
the working of the main part — the man — is rendered
less effective, and that of the lesser part — the hand—
1 That is, of course, supposing the external world and the
properties of matter allowed it to exist at all when in such small
masses : e.g. Lillie has proved that there is a minimum size (deter-
mined no doubt chiefly by surface-tension) below which pieces of
Stentor (a ciliated Infusorium) cannot regenerate. See p. 47.
i] IDEA OF INDIVIDUALITY 11
is stopped for ever. Even in animals with the most
astounding powers of regeneration, the working of
the whole is always impaired, if only for a short time,
by the removal of a part: some regulation, or re-
modelling, is necessary before the mutilated mass is
ready to function as a whole once more. Even such
an animal is a whole and no mere aggregate : it has
an inner principle of unity, which may be loosely fixed
and lightly changed, but is none the less real. Our
hypothetical homogeneous masses have, in themselves,
no inner principle: their definiteness is imposed on
them from without, and one feels that if the external
conditions altered, they would have none of the
independence of our perfect individual, but would
alter blindly with the conditions, like raindrops, which
in ordinary showers are small, but in a thunderstorm,
under the influence of electricity, run together into
large heavy drops showing no sign of their composite
origin. One can, in fact, consider the working of any
portion without the slightest reference to a whole,
and it thus becomes evident that nothing homo-
geneous can be called an individual. Starting from
the just not homogeneous, there can be traced a
tendency towards ever greater heterogeneity running
up through the series of animal individuals. This
was indeed only to be expected. To perfect its
independence, the individual, it was seen, had to
render its actions precise, independent of each other :
12 ANIMAL INDIVIDUALITY [CH.
and in non-conscious organisms at least, difference of
function always implies difference of structure, so that
the more independence — the more individuality — an
individual is to possess depends very closely on the
amount of heterogeneity of its parts. Look for
instance at such an individual as a colony of Termites
("white ants") (cf. p. 142), its defence delegated to
one caste, its nutrition to another, its reproduction
to another ; the various castes are specially adapted
in their structure for their various functions. It is
obvious at once that the queen with her vast swollen
abdomen full of eggs is a much more effective repro-
ducer than if she had retained any of the structure
and mobility necessary to defend or look after her-
self. The soldiers again could not have been such
powerful defenders of the colony if they were to have
kept any of the delicacy of mandible required by the
workers, the craftsmen.
Another illustration : the accurate grasping powers
of the human hand are only rendered possible by its
consisting of a number of distinct but co-ordinated
parts. The action of grasping is an undivided and a
single act, but is only possible because the organ of
grasping consists of separate and different parts.
The pseudopod of an Amoeba, to take the opposite
extreme, has no differentiation of parts: hence the
functions it can perform are few and unprecise.
In both these cases, the dependence of efficient
i] IDEA OF INDIVIDUALITY 13
action, and so of independence, is clearly dependent
upon a visible and obvious heterogeneity of structure.
It might appear self-evident that the organs, the
animal's living tools, should have a different structure
according to the functions they were meant to carry
out, were it not that in man we have the example
prominently before our eyes of an enormous number
of very special functions being executed by a single
organ such as the hand. This apparent exception is
due to the structure of his brain, which has given
him reason and educability for instinct and automa-
tism. True, he has to be at the trouble of exercising
his wits, but gains vast potentialities thereby ; the
brutes have no toils of learning, but their smooth
actions are sadly limited. He has learned to make
tools from inorganic materials, and they serve as the
heterogeneous structures by means of which he can
perform all his diverse actions. For specialised
functions there must always exist specialised struc-
tures; but man through his conscious reason has
beep able to put off the burden of them from his own
'substance on to the broader shoulders of inorganic
nature. There does exist some corresponding hetero-
geneity in himself, but not in visible structure : it lies
in the diversity of his states of consciousness.
These cannot all exist as such at one time1, but by
1 For a case of heterogeneous physical structures which cannot exist
simultaneously, see pp. 110, 113. There the structures must alternate
14 ANIMAL INDIVIDUALITY [OH.
means of the memory, each can be summoned up as
it is wanted. No doubt accompanying them there
are physical and chemical differences in the nervous
tissue, causing differences of continuity between the
various neurones, but this physical heterogeneity is of
no obvious or visible kind. The broad differences,
the differences that can be felt, lie in the states of
consciousness, so that the individual, after advancing
a long way in its march towards perfect individuality
by means of heterogeneity of co-existent structures,
has got to its present position by adding to this a new
device, heterogeneity of states of consciousness, which
states, through not being co-existent, can be more
numerous and more heterogeneous than ever the
structures could.
One last attribute of the individual, but a very
important one. So far the individual has emerged
as " Unity in Diversity." It shows diversity both in
what it is — its physical structure and the architecture
of its consciousness — and in what it does — the actions
which more truly constitute its real essence. It also
has unity, because though all its heterogeneity of
architecture is devoted to producing heterogeneity
with each other in cyclical change ; here, the memory obviates the
necessity for that. Though two states of consciousness cannot
actually co-exist at one moment of time, for all practical purposes
memory permits it, as when we say that a man can attend to his
profession and write a book upon some other subject ''both at once,"
or as when a chess-player plays a dozen games "simultaneously."
i] IDEA OF INDIVIDUALITY 15
of actions, each one of these only has meaning when
considered in relation to the whole. Thus the problem
so far has been the relation of the parts to the whole.
There remains to be considered the relation of this
whole to itself.
Since it is obviously the working, the function,
which is important in an individual, the structures
being only instruments for the function's better per-
formance, this question really resolves itself into the
relation between the working of the whole individual
at one time and its working at another, later time.
This has already been implicitly answered. When
we said that the hand and its functioning had signi-
ficance in relation to a whole, we did not mean merely
to a whole which happened to be there at that one
instant, but to a whole which had a continued exist-
ence in time. When the hand takes up a piece of
bread and puts it into the mouth, that action has
no significance for the whole man if only that instant
of time is considered. Its significance is only seen
later, when the bread has been digested, absorbed,
and carried to nourish all the hungry parts of the
whole individual.
What has been said so far presupposes some
degree of continuance in the individual ; a survey of
the various kinds of organic individuals shows this
continuance to be common to them all, and that too
in no limited measure, but as one of the fundamentals
16 ANIMAL INDIVIDUALITY [OH.
of their existence. Looked at from this point of view,
the individual appears as a machine whose working
has for result no " finished article," the uses of which
do not affect the machine, but merely the continuation
of that same working. The result (and the object)
of the working of a printing-press is to print books :
but the books when printed are of no use to the
press. The result (it is risky to say the object) of
the working of an individual is for it a minute later
to be still working in the same way. There is no
material product given birth to by the process ; but
the result of the working is of the greatest interest to
the individual, the machine that is working.
This fourth view of the individual, as a whole
whose diverse parts all work together in such a way
as to ensure the whole's continuance, or, as the
evolutionist would say, whose structure and working
have "survival-value," cannot stand without some
qualification. There is death to be reckoned with ;
the survival is only temporary.
Under cover of the one word Death lie sheltered
two separate notions — death of the substance, when
the living protoplasm ceases to exist as such, and
death of the individuality informing the substance1.
In man, both are inseparably connected; in many
lower animals they are not. To take the simplest
1 For a fuller treatment of both these conceptions, see an article
on "The Meaning of Death" in the Cornhill Magazine for April 1911.
i] IDEA OF INDIVIDUALITY 17
example : most Protozoa, such as Amoeba or Para-
maecium, definite individuals both, feed and con-
tinually grow, and when they are grown to a certain
maximum size, divide into two halves (see pp. 41, 56),
each of which reorganizes itself into an individual
resembling its " parent." Not a jot of substance has
been lost : but one individuality has disappeared and
two new ones are there in its place.
Owing to the material properties and limitations
of her " physical basis " of protoplasm, Life in her
attempt at perfect individuation has been faced by
a dilemma with which she has never fully been able
to cope.
Growth, the balance of gain over loss in meta-
bolism, is either a necessary attribute of protoplasm,
or else, more probably, an easily-acquired property,
of such all-round usefulness that every organism has
seized upon it (see Roux, 16). At all events it is
universal in all protoplasm throughout all or most
of its active existence. Now if Life allows this growth
to take place indefinitely within the limits of one
individual, two awkward things happen ; first of all,
the mere increase of bulk brings difficulties (see
Chap. II), and secondly the increased weight of the
whole needs some kind of a skeleton or scaffolding
for its support. This skeleton, since living protoplasm
itself is not firm enough, must be built out of dead
materials, mere secretions of protoplasm. These have
18 ANIMAL INDIVIDUALITY [CH.
not Life's power of renewing themselves, of " sprout-
ing fresh and sweet continually out of themselves "
like protoplasm, yet all the time are being exposed
to the inclemencies of the world and the assaults of
enemies: at last something, the oldest part, gives,
and involves the whole fabric in its fall1.
Death of the substance — that has been the result
whenever Life has allowed unlimited growth to the
individual : and when she preserves the substance,
as in the Protozoa, by dividing it into two whenever
it has reached a certain size, so keeping the pattern
of the race within a narrow range, easily controlled,
then there must be death of the individuality. She
has never been able to produce an individuality
which can for ever keep the unstable structure of its
substance nicely balanced against the chance violences
of the outer world.
But — and this is important — when the Protozoan
divided its substance and destroyed its individuality,
two fresh ones sprang up in the two separate masses
of substance. The relation of the organism's in-
dividuality to its substance will be considered at
more length in Chap. VI. Here it can only be said
that protoplasm has primitively a great power of
self-regulation, so that the plan of the individual's
structure which is characteristic for the species can
1 As examples will serve, the hollow trunks of aged trees, the
brittleness of old bones, and the decay of teeth.
j] IDEA OF INDIVIDUALITY 19
exist actual and patent in a given mass of protoplasm,
and yet can also exist, though latent and potential
only, in any and every part of that mass above
a certain minimum size. Break off a Begonia leaf
and chop it into little bits ; each bit reveals its latent
power, sending roots downward, shoots upwards, and
at the last becoming a self-sufficient whole. Through
this regulatory power, Life has been able to save
herself a tossing from her dilemma, escaping, like
a Minoan acrobat, between the very horns : through
it she has the possibility of reproduction.
The essence of reproduction is that one individual
should create a new individual out of itself. The
parent may persist, as in man, after the offspring has
come into the world, or, as in Protozoa, may annihilate
itself in the very act ; that does not matter. What
matters is that in every species there exists a
succession of individuals in time, each one derived
from the very substance of an earlier, each one built
up and working on a common plan. Life has thus
been able to steer a middle course. In the higher
animals, for instance, she has perfected and used the
single individual up to a point, to procure the greatest
amount of independence for herself who animates his
frame ; then, when it becomes difficult, and more
difficult as time goes on, to maintain his supporting
tissues in repair and hold balanced the many pro-
cesses struggling within him, she calls in the power
2—2
20 ANIMAL INDIVIDUALITY [OH.
of reproduction, raises up new individuals of the
same sort out of his substance, and abandons him to
his fate ; but the race goes on1.
Our first definition of the individual based on the
idea of continuance can now be amended. We must
not say that the individual is a whole whose parts
work together in such a way as to ensure that this
whole, and its working, shall persist ; the individual
only persists for a limited time. In spite of this,
something does indefinitely continue, though it is but
the kind, the species, and not the single individual
itself. There is only one kind of working in the
species, and this repeats itself in a recurrent cycle ;
but for each cycle as it recurs a new individual is
required as the instrument of the working2.
1 It is to be noted that no actual impossibility stands in the way
of the individual's continuance, but only great practical difficulties.
Bergson somewhere makes the illuminating remark that the whole of
Evolution might have realized itself in a single individual. This,
with our knowledge of the potential immortality of many kinds of
functioning protoplasm (see Metschnikoff on the age of trees, their
propagation by cuttings, etc.) on the one hand, and of the facts of
embryology, more especially the striking changes that take place at
metamorphosis, on the other, we shall not readily be prepared to
deny ; but Life, gifted with reproductive powers, has found it come
cheaper and easier to choose Death for each single individual and
think rather of the persistence of the race than to expend over-
increasing energy on patching up the defects that are bound to
appear in the individual with age. (See Cornhill, 1911, loc. cit.)
2 It would be more accurate to say at least one individual : often
two or more distinct and unlike individuals are employed in each
cycle of working ; see p. 23.
i] IDEA OF INDIVIDUALITY 21
These qualifications, universally applicable though
they are to all individuals that we know on this earth
are still mere qualifications, not essential to the pure
idea of individuality : the perfect individual would be
eternal, subduer of time as well as of space. Since,
through practical difficulties, Life has not been able
to reach this perfection, she has had to content her-
self with the next best, continuance of the kind of
individual instead of the individual itself.
This, however, is alone enough to rule out of
court the pretensions of all inorganic constellations
to individuality, those even of crystals and of solar
systems. The solar system is a whole most definitely
"isolated by Nature," heterogeneous, and composed
of parts closely inter-related in their working ; what,
besides the objection made above (p. 9), which may
only depend on our ignorance, prevents our calling it
an individual ? This, that its working is not directed
to continuing either itself or other systems like itself.
The crystal has no parts, but is homogeneous ;
were it not, its working would still betray it, though
at first sight its growth and its strange powers of
regeneration display it as functioning to preserve
a special form. Put in a weak instead of a saturated
solution, and it will not simply cease to exist, like
an animal placed in unfavourable conditions, but
will unbuild itself as busily and regularly as just
now it built itself up. Such a combination of two
Fig. 1. Diagram of the life-history of the Liver-fluke. The egg
hatches out into a free- swimming embryo («i) ; this if it finds its
snail changes into a sporocyst (a2) ; this produces inside itself a
number of rediae (b) ; which in their turn each produces a number
of cercariae (GI). These, if conditions are favourable, find their
way into a sheep, where they grow up into the adult Fluke (c%).
(aj — c1} magnified; c2 natural size.)
CH.I] IDEA OF INDIVIDUALITY 23
diametrically opposed and equally active tendencies
can scarcely be called an individual.
The existence of a species or race, a procession
of similar individuals each descended from a previous
one, as well as of what we usually call individuals,
the separate beings that at any one moment represent
the species, leads of necessity to the separation of two
distinct kinds of individuality, one belonging to the
race and one to the persons that constitute the race.
Take as an example Distomum hepaticum, the Liver
Fluke (Fig. 1). The eggs of this unpleasant creature,
which gives sheep the disease known as liver-rot,
are passed out of the host and hatch out into minute
embryos that swim about in the film of moisture on
the meadow-plants. They cannot develop further
unless they fall in with a particular sort of snail : if
so, they burrow into its liver, and grow up, not into
a new fluke, but into an irregular sort of bladder,
the sporocyst] this, from its inner wall, produces a
number of new embryos which grow and burst out
of their parent as the so-called rediae — individuals
differing both from the fluke or the sporocyst. These
in their turn give rise to a number of little tailed
creatures, the cercariae, which migrate out of the
snail, pass into a resting stage on blades of grass,
and there passively await a browsing sheep. If one
by good chance devours them, they hatch out, bore
their way into the liver, and grow up again into flukes.
24 ANIMAL INDIVIDUALITY [CH.
Now each of these three forms that thus cyclically
recur is obviously an individual in the sense defined
by us: they are wholes with diverse parts, whose
working tends to their own continuance, even though
this continuance is limited. But besides this there
is the cycle itself to be reckoned with : it too is a
definite something, a whole, it too is composed of
diverse parts, sporocyst, redia, fluke, it too works
in such a way that it continues (and continues in-
definitely). What right have we to deny it an
individuality as real as those possessed by any of
its parts? True, those parts are separated in space ;
but the ant-colony (p. 142) shows that this is no bar
to individuality. The real point is this : the exist-
ence of the sporocyst and the redia is of no direct
advantage to the individual fluke : it would grow and
lay eggs just as happily if all the host-snails, and with
them all sporocysts and rediae, present and to come,
were exterminated. It is however of advantage to
something, and that something can only be the race
of liver-flukes, the kind of protoplasm which by its
difference from other kinds has earned a special
name — Distomum hepaticum.
That is an extreme case; the two kinds of
individuality may often be inextricably interwoven.
What is of advantage to one is usually of advantage
to the other, so that, by an over-emphasis of the
species-individuality of which we are the parts, it
i] IDEA OF INDIVIDUALITY 25
is often said that our bodies are only " cradles for our
germ-cells."
It must here suffice to say that wherever a re-
curring cycle exists (and that is in every form of life)
there must be a kind of individuality consisting of
diverse but mutually helpful parts succeeding each
other in time, as opposed to the kind of individuality
whose parts are all co- existent: the first constitutes
what I shall call species-individuality, or individuality
in time, while the other corresponds to our ordinary
notions of individuality and, if a special term is needed,
may be called simultaneous or spatial individuality.
It is of individuals of this latter class that we have so
far been speaking, and to them we must now return.
Our minimum conception of continuance — the
continuance of the kind of individual rather than
of the single individuals themselves — is thus a touch-
stone to distinguish between what is and what is not
an individual : it now remains to trace the progress
of continuance on this earth up towards the un-
attainable maximum of the undying. At the start,
the individual in such organisms as bacteria has a
duration reckoned merely in hours or even in minutes.
There is but the hastiest procession of never-returning
forms across the stage of the species. As we ascend
the scale, the individual learns to stay longer and
expound his part more clearly. With the attainment
of the multicellular condition and the possibility of
26 ANIMAL INDIVIDUALITY [CH.
reproduction by detaching one small part of himself
instead of by division of the whole (p. 45), he can
even linger on the stage till the next scene is half
played through.
In the actual duration of his life, the individual
ranges from the bacterium's hour to the big tree's
five thousand years. So far the direct and obvious
path can lead. But consciousness once more has
found out a way more subtle and more effective.
Man in this again stands on the pinnacle of individu-
ality— not in mere length of days, but in having found
a means to perpetuate part of himself in spite of death.
By speech first, but far more by writing, and more
again by printing, man has been able to put some-
thing of himself beyond death. In tradition and in
books an integral part of the individual persists, and
a part which still works and is active, for it can in-
fluence the minds and actions of other individuals in
different places and at different times : a row of black
marks on a page can move a man to tears, though the
bones of him that wrote it are long ago crumbled to
dust. In truth, the whole of the progress of civiliza-
tion is based on this power. Once more the upward
progress of terrestrial life towards individuality has
found apparently insurmountable obstacles, gross
material difficulties before it, but once more through
consciousness it finds wings, and, laughing at matter,
flies over lightly where it could not climb.
I] IDEA OF INDIVIDUALITY 27
One word more on continuance. The continuance
of the working of a species as we have defined it
would preclude change ; but change and the idea of
evolution are at the base of all modern thought in
science and philosophy alike. As a matter of fact,
the resemblance of the working of one individual to
its result, the working of a descendant individual, is
never absolute : and so, since working and structure
are inter-dependent, no two individuals are ever
exactly alike in appearance and architecture. Given
this fundamental fact of variation, nothing is im-
possible: and to-day few would be found to deny
that all the battalions of living organisms are de-
scended from one primeval type. That is the logical
outcome of the doctrine of Evolution. Evolution is a
word glibly used, but often without thought of its full
meaning. If Evolution has taken place, then species
are no more constant or permanent than individuals.
We know what we mean when we use the words child
and man, and we know that at puberty comes the
crisis which transforms the one into the other; but
the whole process is continuous. So we know what
we mean by a species ; probably, too, there are crises
when the species becomes unstable and in a short
time we can say, "here is a new species." None the
less the one species, if we accept the idea of Evolution,
is continuous with the other by the most obvious
continuity, that of its substance. As individual
28 ANIMAL INDIVIDUALITY [CH.
emerges from individual along the line of species, so
does species emerge from species along the line of
life, and every animal and plant, in spite of its
separateness and individuality, is only a part of the
single, continuous, advancing flow of protoplasm that
is invading and subduing the passive but stubborn
stuff of the inorganic.
From this short survey of the types and tendencies
of existing individuality, three things emerge. First
comes the minimum conception of an individual; the
individual must have heterogeneous parts, whose
function only gains full significance when considered
in relation to the whole; it must have some inde-
pendence of the forces of inorganic nature ; and it
must work, and work after such a fashion that it, or
a new individual formed from part of its substance,
continues able to work in a similar way.
Then comes the idea of the perfect individual-
something unknown to our senses, its characters a
mere raising to infinity of those enumerated above.
Defining those characters in different form, we may
say that such a being would possess perfect internal
harmony, and perfect independence (in our particular
sense) of matter and of time itself.
Lastly, and this is perhaps most important for
the present quest, there shows the actual line traced
by Life in her progress up towards this perfect
individuality. She has had to contend with the
i] IDEA OF INDIVIDUALITY 29
limitations of her own physical basis, and the result
achieved is a compromise ; not what she planned, but
what her imperfect materials allowed her to carry
out — the old difference between the poem flashed on
the poet's brain and the same poem on paper, striving
to gleam through the words that build it.
Her track is straightforward at first : she tries
to realize to the full the possibilities of her material
basis, increasing the mere size, the mechanical com-
plexity, and the length of life of her individuals, but at
last there comes a point where she can go no further
forward — the spirit is willing, but the flesh is weak.
So far, range of action has been dependent upon
actual mass of substance, diverseness of action upon
complexity of substance, and length of action upon
duration of substance. Now this direct way is barred :
but she finds out another path. She produces a unique
type of mechanism, of which the most fully developed
type is the human brain, and, associated with it, the
power of conscious reason and of memory. At once
the individuality is released from waiting servile upon
substance. Now to its own size it can add the size of
all its tools and machines — by them now is measured
the Range of its action : the Diversity of its action it
has multiplied a hundredfold by substituting indefinite
potentialities for necessarily limited actualities ; and
the Duration of its action, by the device of language,
now far surpasses the allotted span of its substance.
30 ANIMAL INDIVIDUALITY [OH.
To such an individuality, one that can thus
transcend the limits of its substance, the name of
Personality is commonly given. Man alone possesses
true personality, though there is as it were an aspira-
tion towards it visible among the higher vertebrates,
stirring their placid automatism with airs of con-
sciousness. In man, personality is usually defined
with reference to self-consciousness rather than to
individuality ; but the power of reflection and self-
knowledge is linked up, in our one type of personality
at least, with the new flight of the individuality-
conscious memory seems necessarily to imply a vast
increase of independence, so that it is all one whether
we define the possessor of a personality as a self-
conscious individual, or as an individual whose
individuality is more extensive both in space and
time than the material substance of its body.
Personality, as we know it, is free compared with
the individuality of the lower animals ; but it is still
weighted with a body. There may be personalities
which have not merely transcended substance, but
are rid of it altogether : in all ages the theologian
and the mystic have told of such "disembodied
spirits," postulated by the one, felt by the other, and
now the psychical investigator with his automatic
writing and his cross-correspondences is seeking to
give us rigorous demonstration of them.
If such actually exist, they crown Life's progress ;
n] BIOLOGICAL FOUNDATIONS 31
she has started as mere substance without individu-
ality, has next gained an individuality co-extensive
with her substance, then an individuality still tied to
substance but transcending it in all directions, and
finally become an individuality without substance, free
and untrammelled.
That for the present must be mere speculation.
The Zoologist has strayed : he must return to his
muttons and his amoebae, and in the next chapter
will begin to consider more closely the actual facts
of animal individuality and their probable explana-
tion.
CHAPTER II
THE BIOLOGICAL FOUNDATIONS OF INDIVIDUALITY
THE idea of individuality, in common with most
other large biological problems, came to be first
considered — as indeed was only natural — from the
standpoint of man alone. With the growth of our
knowledge concerning invertebrate animals, the ideas
thus gained had to be considerably modified, until
finally the theory of evolution once and for all justified
the more advanced among the earlier thinkers, and
showed that in any view of animal individuality as a
whole, we must not take man and mammals as the
32 ANIMAL INDIVIDUALITY [OH.
single starting-point whence we could logically work
backwards to all the rest of the organic world, but
must regard them as an ending instead of a beginning,
and, what is more, as but one ending among many.
From the single beginning, many lines have branched
out to the many endings, and the only logical method
is to start from the beginning (where, too, the
phenomena themselves are far less complicated) and
trace out each line to its ending, instead of trying to
bring the various endings into relation with each
other. Each ending is only intelligible through its
history, and the history of one is different from the
history of another.
The one advantage possessed by the anthropo-
morphic view of individuality (which, as a half-
unconscious product of every-day experience, is still
held by the great majority of those who are not
professed biologists) lies in its dealing with long-
familiar things. Since, however, this is a very real
advantage to those who are approaching a subject
the major part of which is bound to be not at all
familiar, "full of strange oaths," and so bristling with
new names that " bearded like the pard " is scarce a
stretch of metaphor, we shall begin here with man ;
thence, taking stock of the more obvious facts of
comparative anatomy, with the historical or evolu-
tionary idea to aid us, try to extend the conception
from man to the rest of the animal kingdom ; then
n] BIOLOGICAL FOUNDATIONS 33
we shall have to show some of the chief difficulties
which attend upon this point of view; and finally,
having thus cleared the decks for action, we shall be
able to take up our subject anew from its historical
and logical beginnings.
A normal adult man or woman is an organism,
whose complicated and varied parts are almost all
designed for one end — to prolong the existence of the
whole to which they belong1. It is in fact a machine
which has the power of running itself, independent,
within wide limits, of what is happening in the rest
of the world. Unlike our artificial machines, however,
whose working is constant, and whose only change is
one of wearing-down, the running of the organic
machine leads to changes in the actual structure of
the machine, and so to changes in its working. We
develop of necessity, of necessity we age, and at the
last we die. But we remain the same individual
throughout — on that all common use is agreed. Till
death, when we obviously cease to be whatever we
have been before, we preserve our individuality in
spite of all fundamental differences in appearance
and behaviour. But as to our nature before birth,
there the common view is at a loss ; its uncertainty
1 Those which do not serve this end (with the exception of some
which appear to be " accidental" by-products due to the interaction
of the purposeful factors) are of course destined to help in repro-
duction.
H. 3
34 ANIMAL INDIVIDUALITY [CH.
has found expression in Milton's words, when to
Limbo he consigns, not " Eremites and Friars " only,
exiled thither for theological reasons, but " Embryos
and Idiots " as well.
The very conjunction of his words will help us out
of the difficulty. In our thought, the ide'a of human
individuality has become interwoven with that of
personality — a purely mental attribute. Even though
by embryo Milton meant abortion, the lack of
mentality — of personality and of soul, if you will,
which it shares with the idiot, is the same whether it
be within or without the womb, and he was right in
regarding its fate as a grave theological problem.
But (though the reasons for the defect of mental
power are different in the two cases) an embryo
cannot because it lacks personality be considered to
lack individuality too, any more than an adult idiot
can, although the individuality is no doubt less intense
or perfect than in the normal adult man. It is this
confusion of personality and individuality that raises
most doubts in the mind of the average man as to
the claims of the foetus to be called an individual.
The other chief doubt arises from its incapacity to live
out of its mother's body. But reflection will show
that the embryo is like every other living thing in being
able to exist only under certain defined conditions,
wrhich are merely much narrower for it than for the
adult man and the generality of animals. (See p. 132.)
n] BIOLOGICAL FOUNDATIONS 35
Thus we can take the individuality of man back
before birth to a stage when the embryo ceases to be
easily recognized by the naked eye. To trace it still
further, the man of science with his microscope and
his knowledge of simpler animals must step in. There
the ordinary man must pause, and there we will leave
the question for the present ; turning now to see how
far his anthropocentric notions of individuality radiate
out to other living things.
We find that he unquestioningly applies the word
to all the familiar creatures of everyday acquaintance,
the four-legged beasts and the birds, the snakes
and the fishes. This is his unconscious Comparative
Anatomy — he recognizes instinctively the community
of general plan he shares with them. This unconscious
reasoning will carry him still further : he will not
hesitate when it comes to snails or insects or worms
—in fact, show him anything with a mouth and
a stomach and he will dub it an individual. So far,
all seems plain sailing.
In reality, this is exactly where all the difficulties
begin : without studying the outward form and minute
structure of himself and of other animals at all stages
of development — without some knowledge, that is to
say, of all the numerous branches of the science of
Zoology, — it is impossible for him to extend his
knowledge of individuality any further, and when he
does call Zoology to his aid, he finds that in every
3—2
36 ANIMAL INDIVIDUALITY [CH.
direction it seems to lead to contradictions, raising
difficulties worse than those it lays. To start with,
he has been considering till now only those of the
lower animals which slip naturally into u scheme
taken from the pattern of Man. A mustering of all
the clans soon reveals numerous types of animals that
will not fit this frame at all.
There are communities, such as those of bees and
ants, where, though no continuity of substance exists
between the members, yet all work for the whole and
not for themselves, and each is doomed to death if
separated from the society of the rest.
There are colonies, such as those of corals or of
Hydroid polyps, where a number of animals, each
of which by itself would unhesitatingly be called an
individual, are found to be organically connected, so
that the living substance of one is continuous with
that of all the rest. Sometimes these apparent
individuals differ among themselves and their energies
are directed not to their own particular needs, but
to the good of the colony as a whole. Which is the
individual now ?
Histology then takes up the tale, and shows that
the majority of animals, including man, our primal
type of individuality, are built up of a number of
units, the so-called cells. Some of these have con-
siderable independence, and it soon is forced upon us
that they stand in much the same general relation to
II]
BIOLOGICAL FOUNDATIONS
37
the whole man as do the individuals of a colony of
coral polyps, or better of Siphonophora (p. 119), to the
Fig. 2. Portion of colony of Bougainvillea fruticosa, magnified,
p, polyps; m, medusae; mb, medusa-buds. (From Lubbock,
after Allman.)
whole colony. This conclusion becomes strengthened
when we find that there exist a great number of
38 ANIMAL INDIVIDUALITY [CH.
free-living animals, the Protozoa, including all the
simplest forms known, which correspond in all
essentials, save their separate and independent
existence, with the units building up the body of
man : both, in fact, are cells, but while the one
seems to have an obvious individuality, what are
we to say of the other ?
So far we have treated the problem statically, as
it were : when we come to view it dynamically,
tracing the movement of life along its course, the
difficulties do but increase. Take, to begin with, a
simple colony of Hydroid polyps (Fig. 2), and ask how
does this multiplicity of connected animals arise ?
Observation shows the whole stock to be formed, by
a process of budding, from one original individual.
A little lump or knob is seen at one place, which,
growing rapidly, bit by bit assumes the appearance
of the individual whence it has sprung ; it takes its
origin in a small group of cells (not in a single one)
and its growth depends on continued growth of the
substance of these cells, accompanied by their re-
peated division. By this means, the first individual
produces a second out of itself. Its own individuality
is not lost in the process ; it is, however, impaired,
for though the creature's organization is practically
the same as it was before, yet it is no longer separate
in space, and that part of it below the bud's point
of origin is now the common property of the two
II]
BIOLOGICAL FOUNDATIONS
39
individuals. The second individual and the re-
maining members of the colony, which are all formed
Fig. 3. Hydra, semi-diagrammatic, showing a bud-rudiment on the
right and an advanced bud on the left, m, mouth ; t, tentacles ;
t', tentacles of bud. (Magnified.)
40 ANIMAL INDIVIDUALITY [OH.
in the same way, differ from their original only as
regards their mode of development and, as a con-
sequence of this, in never having enjoyed a free and
full individuality. The relation of the individuals in
a colony to each other is thus rendered still more
obscure owing to the fact of one being produced out
of another. What was at first nothing but a part
grows up into a new whole.
Budding, though perhaps most striking when it
leads to the formation of a colony, is by no means
restricted to colonial forms : often, as in Hydra
(Fig. 3), the process is completed, and the bud set
free to lead an independent life. Here one individual
has produced a second out of its own substance : the
two resemble each other not less closely than two
individuals bred from the egg, and yet the first has
lost not a jot of its own individuality in thus creating
itself anew in the second.
This fresh creation of new forms from the substance
of the old is what we usually term Reproduction.
Budding is but one of its many methods, and we
must look at some others before we can see its full
bearing upon our subject. First we will take fission,
or division into two halves, a method which occurs in
several groups of the higher animals, though less
commonly than budding. Rarely, as among the
stony corals, are colonies produced through its
means ; usually the two halves part company and each
n]
BIOLOGICAL FOUNDATIONS
41
If !£3 II
- & ^
^ &
.2 . a « ^
Illgflf
3
42 ANIMAL INDIVIDUALITY [CH.
becomes as perfect an individual as its parent. It is,
however, in this relation of parent to offspring that
division is at variance with budding. Instead of one
individual producing another, here the founder of the
race ceases to exist, losing his own individuality in
the production of two fresh ones. A glance at
Fig. 4 will show that the whole substance and the
whole organization of the first individual is separated
in division into two discrete masses, each of which is
incomplete in possessing only half the normal structure.
These incomplete individuals, in the examples we have
chosen, and in many other animals as well, do not as
one might expect complete themselves by keeping the
old half-organization intact and budding out what is
missing, but, by a method involving a more radical
destruction of the parent's individuality, they remodel
their structure by a strange internal mason's-work,
turning the materials that but now constituted a half-
individual into a whole. From their parent they
receive the half of its substance and the half of its
organization ; they make a new organization without
adding to the substance1. Growth subsequently
increases their size without altering their individuality
or organization, until, on attaining to the prescribed
1 Or at least without adding more than a very small amount.
Normal growth may go on, but the re-modelling goes on still faster.
That growth and reorganization are not necessarily connected is
shown by the strange facts narrated on p. 145.
n] BIOLOGICAL FOUNDATIONS 43
limit, they repeat the process. Division is thus even
more important for the present purpose than budding ;
we have the strange paradox that though each in-
dividual hands on the whole of its substance intact
to its successors, yet with this perfect continuity of
substance there co-exists perfect discontinuity of
individualities.
There remains the third chief mode of reproduc-
tion. In considering the hydroid colony, we found
that all its members took their origin, by budding,
from one single founder. This founder, though
identical in organization with the rest, has yet not
had the same origin as they. Tracing its life back-
ward towards its source, we find it first of smaller
size; then comes the stage when its organs are
developed one by one, much as in the bud ; before
this it exists in a form through which the budded
individuals never pass — as a small drawn-out ovoid,
actively swimming instead of fixed to the ground;
before this again it is seen as a round motionless
body, built up like a mulberry out of rounded parts,
and finally its "fount of life" is revealed in a spherical,
inert mass, single and undivided — the fertilized egg.
This fertilized egg is neither more nor less than
a cell — specialized, as one would expect, for the
discharge of its own particular duties, but still a cell.
Here is a further strengthening of our view of the
higher animal or metazoan as a colony of units each
44 ANIMAL INDIVIDUALITY [CH.
comparable with a protozoan1. When the method is
traced by which the plurality of cells in the adult
arises from the single cell of the egg — the method,
that is, of cell-reproduction — it is found to be identical
with one of the ways of reproduction in metazoan
individuals, that of fission ; the single founder of the
cell-community, the egg, divides the whole of its
substance into two halves, each of which is a new
cell. This is repeated again and again, and the whole
army of cells in the full-sized hydroid are direct
descendants of that single founder-cell. But the
hydroid is itself a founder ; and the new "individuals"
which it buds out depend for their growth upon this
same process of cell-division continually repeated.
The paradox is growing yet. Each hydroid seems
in its way a whole ; yet it is as well a mere part of a
single greater whole, the colony, and, besides this,
itself composed of units each of which again is in
some sort a whole : and each whole has some claim
to the name of Individual.
One gap still yawns : what was the origin of the
single cell that gave birth to the whole adult organism?
In this particular case, it was a fertilized ovum : by
which is implied that the single cell has arisen from
the total fusion, body and soul, or rather cytoplasm
1 The animal kingdom is divided into the two primary sub-
kingdoms Protozoa or single-celled animals, and Metazoa or many-
celled animals.
n] BIOLOGICAL FOUNDATIONS 45
and nucleus, of two other cells, these are technically
known as the gametes, and their product, the fertilized
ovum, as the zygote. These two cells have come from
two separate individual persons (one male and one
female) and their cell-ancestors have been firmly
built into the fabric of those individuals' bodies.
This merging of two cells and their two in-
dividualities in one (the exact reverse of fission) is
the essential sexual act, and is usually known as the
conjugation of the two cells. It will be considered
more fully later (p. 71); here it does not concern us,
for, as Weismann and others have conclusively proved,
reproduction and conjugation are in their origin
totally distinct from each other. In all the Metazoa,
however, conjugation is always connected with repro-
duction, so that the fusion of two cells always implies
the production of a new individual. In ourselves, and
all other Vertebrates, the converse also is true, that
the production of a new individual always implies the
previous fusion of two cells — reproduction, in other
words, is always sexual: but in very many of the
lower Metazoa, though conjugation leads to repro-
duction, reproduction may occur independently of
conjugation. Two examples of this asexual reproduc-
tion have been seen in budding and in fission.
Thus the complication introduced by the fusion
of the two gamete-cells into the otherwise unvaried
succession of cell-divisions does not really affect the
46 ANIMAL INDIVIDUALITY [CH.
present question, the relation of one individual to
another. The essential point lies in the continuity of
individual with individual.
To add the final straw, regeneration comes. Re-
generation is usually looked on as something strange,
almost abnormal, owing to its not occurring in man
or his animal familiars. In reality it is much rather
an original property of life, which for special reasons
has dropped out of the human scheme of things.
As we descend the vertebrate scale, it is not until
we reach the lower Amphibia, such as the newt and
salamander, that regeneration becomes at all marked.
Even here it is present in a restricted form, and is
confined to the restoring of lost organs. A leg, that
is to say, or a tail, even an eye or a jaw may be re-
placed, but the central systems and main lines of
organization must be left intact. There must remain
a certain central residue of the individual if it is to
complete itself.
This in itself points to a vaguer, more fluid notion
of individuality than can ever be got from contem-
plation of man alone, but what are we to say of such
things as happen in many of the lower animals ? Take
first one form of regeneration seen in Clavellina, one
of those poor relations of Vertebrates, the Ascidians.
Cut Clavellina across in the middle, and (in certain
defined conditions) a bud will sprout from the front
end of the hinder half, and another from the hinder
n] BIOLOGICAL FOUNDATIONS 47
end of the front half. As in the growth of the
hydroid colony, the old organization is kept entire
and whole, the new organization is built up in the
bud; here, however, it is not one whole individual
giving rise to another, but one half giving rise to just
that dissimilar half which is its complement. What
is more, both the unlike halves of the original whole
can thus add what is wanting — that and no more—
to bring them up to the rank of wholes again. There
is an old school-boy question about a cricket bat :—
suppose the handle of a bat broke, and a new one
was put on .to the old blade. Suppose then that the
blade broke and was in its turn replaced ; would the
bat still be the same bat ? That is a hard question,
but Clavellina asks a harder still.
From this to the extremes of regeneration, such
as occur among flatworms and protozoa, is another
large step. Stentor, for instance (a protozoan which
happens to be specially convenient for experimental
purposes), may be chopped, broken, or shaken up
into pieces of all sizes and shapes, and every piece,
provided only that it is above a definite minimum
size (less than ^ inch in diameter, and in bulk only
1 or 2 per cent, of a full-grown Stentor), and that it
contains a piece of the nucleus, will blossom out as
a minute but fully-formed individual, which will feed
and grow and be indistinguishable from a product of
natural generation.
48 ANIMAL INDIVIDUALITY [OH.
By now, all faith in man as a guide to individuality
must have been shattered. In man, an individuality
presents itself as something definite and separate from
all others, something which animates a particular
mass of matter and is inflexibly associated with it,
appearing when it appears and vanishing only when
it dies. That idea of individuality is not universally
applicable.
In perplexing procession before us there have
appeared individualities inhabiting single cells, others
inhabiting single cells at the start, many cells (and
each of these with some kind of separate inhabitant
of its own) in later life : individualities whose fleshly
mansions are continuous one with another, no boun-
daries between: individualities that appear and
disappear along an undying stream of substance,
the substance moulding itself to each as the water of
a stream is moulded in turn to each hollow of its bed :
within one individuality others infinite in number,
lying hid under the magic cloak of potentiality, but
each ready to spring out as if from nowhere should
occasion offer.
Nothing remains but to abandon preconceived
ideas. We must seek to interpret human individuality
not as the one true pattern to which all others
must conform, but as something with a history and
intelligible only through that history. We must
therefore make for the first beginnings of things and
n] BIOLOGICAL FOUNDATIONS 49
trace their upward progress. For this to be adequately
done, the very fundamentals must be explored, and
the quest begin with an enquiry into the original and
essential properties of living substance.
The biologist, looking at life objectively, finds
life then manifest itself as the sum of the properties
pertaining to a group of peculiar and complicated
chemical bodies which are classed together under the
general name of protoplasm.
The form and structure adopted by the lowliest
living things at the time of their origin, which then
had to serve as the starting-point for all subsequent
forms and structures in life, are chiefly due to two
properties of these protoplasmic substances — one
physical, the other chemical. The first is their
colloidal nature, which permits of their sharing the
definiteness and resistance of solids with the mobility
and quick chemical reactions of liquids. The second
is their power of assimilation, their power of building
up, out of materials different from and chemically
simpler than their own substance, new molecules,
identical in composition with the old. Assimilation
is molecular reproduction, and is by far the most
important property of protoplasm. Whenever an
organism performs any action, it must needs do
work, expend energy. This energy it procures from
the break-down and combination with oxygen of
some of the unstable living molecules. Combustion
H. 4
50 ANIMAL INDIVIDUALITY [CH.
is here associated with chemical decomposition : the
result is not mere oxidized protoplasm, not protoplasm
at all, but various more stable and more oxidized
compounds. Every action thus necessitates the
destruction of some of the living substance, and were
it not for the assimilatory power, whereby it can pick
up materials from the outer world and force them to
assume a structure and arrangement like its own, all
protoplasm would soon vanish into nothingness.
From these two fundamental properties of proto
plasm we can understand three important and almost
universal qualities of living things1. First, their
existence as definite bodies marked off in space and
separate from other bodies, no mere formless collec-
tion of molecules, here to-day and gone to-morrow,
like a liquid or a gas ; secondly their power of move-
ment; and thirdly their growth, due to their building
up more protoplasm by assimilation than what they
destroy in the production of energy. These three
are all of importance in understanding the origin of
organic individuality. Given cohesion of parts, your
primeval organism is marked off from the rest of the
world. Even though it may be homogeneous, no true
1 Almost universal, for it will be seen later that mental powers
have made possible such organisms as an ant-colony, which is not
a solid whole, single and denned in space ; and growth and mobility
may be in abeyance for long periods, though always present in some
stage of an organism's life.
ii] BIOLOGICAL FOUNDATIONS 51
system of diverse parts, yet this mere fact of existence
as a single and separate material body is a first step
towards Bergson's " closed system." In non-conscious
animals, indeed, where individuality is bound down
within the limits of physical substance, this separate-
ness in space is the only foundation upon which such
a closed system could be built. Besides this, it
presents itself as a whole unit to the forces of the
outer world: living substance thus starts with its
foot upon the ladder leading to independence, for
its molecules cohere, and all know that union is
strength.
Given the complex molecules of fixed composition,
and, if of various kinds, existing in a fixed proportion,
there will be definiteness of shape and action ; and
given assimilation — the reproduction of new molecules
identical with the old — there is the possibility of
continuance for this shape and this action.
Analysed thus far, our organism has revealed itself
as very similar to a crystal in its definite boundaries,
definite and permanent form, and, we may add, in its
capacity for growth. It differs only in having a mode
of working as well as a form which is continuous.
The organism, however, has two further properties
which make it at once more definite and more in-
dependent than the crystal. It is more independent,
more self-determining, because it can build up its
complicated molecules out of simple substances, and
4—2
52 ANIMAL INDIVIDUALITY [CH.
because these substances — its food — may be varied
to a considerable extent and the end-result, its
protoplasm, yet be the same. A crystal on the other
hand, cannot build up the complex from the simple
—it can only add ready-formed molecules to its
substance, and can only use them if they are presented
to it in one particular way, in the condition of a
saturated solution.
An organism is more definite because its size is
defined as well as its form. A crystal will continue
to grow without limit if only the appropriate mother-
liquor in which it hangs is kept saturated : its form is
definite, its size indefinite. It is a fact of common
observation, however, that each organism has a
typical size — not invariable, but fixed within certain
not very wide limits. This again is due to the
differences in the modes of assimilation of crystal
and living thing. In the crystal, growth takes
place entirely at the surface. Its assimilation is
purely physical: it assimilates to its own physical
state molecules of the same chemical composition but
in a physical state different from its own. Capturing
molecules from their state of solution, it builds them
up on its solid self in such wise that they fit on to the
pattern of the already existing structure.
With protoplasm, however, assimilation is chemical
as well as physical, and growth takes place by intus-
susception, not by accretion. That is to say, it works
ii] BIOLOGICAL FOUNDATIONS 53
with raw materials1, and these materials, instead of
being plastered on to the outside, can and do pass in
to the interior, and only there are worked up into
those combinations of brick and architect, the mole-
cules of protoplasm. Thus, though the absorption of
raw materials must of necessity take place at the
surface, the actual formation of new living matter, or
in other words assimilation and growth, goes on only
in the interior.
As a further result of its partially fluid nature,
protoplasm is subject to the laws of surface-tension,
and a mass of it will therefore tend to become
spherical. But in a sphere, as in any other solid body
of fixed shape, surface increases with the square, bulk
with the cube of the diameter. When we say that
one ball is three times as big as another, we usually
mean that its diameter is three times as long, for-
getting, or leaving implied, that in surface it is nine
times, in cubic content twenty-seven times as big.
With our balls of living substance, this disproportion
between increase of bulk and increase of surface
brings difficulties.
Every molecule in the inner parts of the sphere
must have oxygen and food if the whole is to go on
living. As the organism grows, that is to say as its
1 Though, as in commerce, one organism's manufactured article is
another's raw material ; take as an example the quadruple chain of
nitrogen-fixing bacterium, clover, ox, and man.
54 ANIMAL INDIVIDUALITY [CH.
molecule-population increases, the demand of each
molecule is no less, but, owing to the disproportion
between surface and volume, the supply available for
each is dwindling. The actual materials of supply
still exist in unlimited quantity, but the organism
cannot get at them. If the English Nation, with
population advancing by leaps and bounds, were not
able to build harbours and provide dock-labourers as
quick as she bred men, all the wheat in Canada, with
Imperial Preference to help, would not keep her from
starvation, for the simple reason that it could not
get in.
So the primeval drop of protoplasm, earliest
ancestor of all living organisms, the English Nation
not forgotten, found, as it grew, its ports and landing
facilities not keeping pace with the demands upon
them. Each particle of food and oxygen has to be
handled by the surface molecules — unloaded from the
circumambient water, loaded up again into solution in
the general protoplasm — before the central populace
can feed or work ; and for each four-fold increase of
the transport workers there is a sixteen-fold increase
within of the mouths to be fed. This cannot go on
indefinitely : but what is to be done ?
There are two alternatives. One is for the mass
of protoplasm to continue its growth, but obviate the
difficulty by spreading itself out in one plane. In
such a film of uniform thickness, whatever its extent,
ii] BIOLOGICAL FOUNDATIONS 55
surface and volume will increase in almost equal
proportion. This method, though it has been used
here and there, is not easy of adoption, nor wholly
satisfactory when adopted. To obtain a thin film
instead of an approximately spherical mass of proto-
plasm, the surface-tension must be very materially
altered, and this implies a deep and continuous
change in the condition of the surface layer as the
size of the whole increases. For main result, the
method has the suppression or at least the delaying
of reproduction. Logically it leads to unlimited
growth of the single mass of living matter, so putting
all the eggs of the species in one basket ; and even
though it is certain that in such a flimsy unco-ordinated
film parts would at length be accidentally torn off or
simply pull apart from the main body, so reproducing
and dispersing the species, yet this reproduction
would be long delayed, and the change of structure
which involved the delay would have brought few
compensating advantages.
The other method is probably easier of adoption,
certainly more beneficial in immediate result. It
consists in this, that the disproportioned mass of
protoplasm divides into two halves. By this means,
though the total volume of living substance is left
unaltered, the total surface it exposes is increased by
over 50 per cent., and the two halves can thus go
on gaily growing until the time comes to repeat the
56 ANIMAL INDIVIDUALITY [OH.
process. The actual division seems to be effected by
a mere temporary lessening of surface-tension in
certain regions, so that this would probably be the
way of least resistance for the organism, the way that
involved less deep-seated change than the first method.
In its results it is certainly better. The species (by
which is meant simply the kind of protoplasm), by the
repeated formation and subsequent wandering away
of new separate masses of protoplasm, is widely dis-
persed, so that it no longer presents a single neck by
the severing of which some Nero of an accident could
with one stroke exterminate the race.
It is thus almost entirely a direct result of the
essential properties of protoplasm, scarcely at all an
adaptation to outer conditions, that the earliest forms
of life defined and limited their size ; — in other words,
that the first stable phase reached by life in her
development on this earth was one in which she
manifested herself as a succession of separate pro-
toplasmic units, each formed from the bipartition of
a former one, each beginning its existence as a rounded
body of definite but always microscopic size, and each
gradually growing, while preserving its form, till its
volume was about doubled, when it divided and left
its two halves to repeat the cycle. These, the primary
units of life, are usually called by the name of 'cells1,
1 Some biologists wish to restrict the term cell to protoplasmic
units with a formed nucleus. The nucleus, however, has certainly
n] BIOLOGICAL FOUNDATIONS 57
and the cell is the historical basis of organic in-
dividuality.
Protoplasm at its first appearance was presumably
a homogeneous substance ; as long as it remained so,
these masses into which it segregated, however definite
their size, their shape, and their reproduction, were
yet not individuals. In their working they are like a
host of other chemical substances, blindly forging
ahead with their reactions, ceasing if the outer con-
ditions transgress certain limits, continuing the same
as long as they remain within those limits. They are
not, in the strict biological sense of the word, adapted
to their surroundings1, they are not adapted any
more than such a cyclical or catalytic reaction as that
which takes place in the manufacture of sulphuric
acid from sulphur dioxide, water, and oxides of
nitrogen. These, much after the fashion of protoplasm
arisen by internal differentiation (p. 60), so that the lowest non-
nucleated moneron, the complex protozoan, and the specialized
metazoan tissue-cell are all homologous, and some word is required
which will cover them all. Whether a mass of protoplasm is
nucleated or not is of importance, but it is of still more importance
to know whether it has arisen by a series of divisions from a primary
unit of life, and so whether it is itself a primary unit. Such units we
shall here call cells.
1 It will be objected that the change in surface-tension permitting
binary fission is adaptive or purposeful. This is quite true, but the
adaptation is concerned only with the race ; it is the first step towards
a species-individuality. The cells within the species, however, remain
unaffected.
58 ANIMAL INDIVIDUALITY [CH.
as it builds itself up and breaks itself down, the
unstable intermediate substance, nitrosylsulphonic
acid, must continually make, unmake, and remake
itself. As long as the raw materials are present in
the right proportions, the reaction will go on in-
definitely. So it is with protoplasm : the conditions
under which the inorganic reaction can take place
are merely more restricted, so that for it to continue,
man must step in with elaborate mechanisms to
ensure adequate supplies of the substances concerned,
provision for their due mixing, care for the removal
of their by-products.
Any machinery that protoplasm makes for facili-
tating its reactions it must not only make itself, but
actually out of itself. So it comes about that any
improvement in working must mean some change in
the structure of the protoplasm, and since improve-
ment usually means division of labour, improved
working brings with it a visible differentiation of
parts in the previously homogeneous cell. What
was a cell and nothing more is now a cell arid an
individual to boot.
Our primitive homogeneous masses of protoplasm,
though all the evidence leads us to assume them, are
purely hypothetical. Every cell that we know to-day
contains at least three, and probably more, diverse
and mutually helpful substances. There is the outer
layer, whose primary function is absorption, though
n] BIOLOGICAL FOUNDATIONS 59
the secondary one of protection is often added. Its
surface-tension and its solubility must be such that
bodies which adhere to it and dissolve in it are useful
to the whole cell as food. Within this outer sheath
are two further substances. One, called chromatin
on account of its affinity for many dyes, is chiefly
concerned with assimilation, with the constructive
part of the protoplasm's chemical cycle. Usually it is
all massed to form (together with other substances) a
definite body or nucleus, but in various primitive forms,
such as some bacteria and some flagellates, it appears
in the shape of minute granules scattered at random
in the mass of the third substance, which, constituting
the bulk of the cell, is called the cytoplasm. This
has as its special duty the destructive part of meta-
bolism ; it liberates energy, and uses that energy in
doing work, such as locomotion, for the good of the
cell as a whole.
All forms of life now living must have had an
ancestor which existed under this double form of
a cell and an individual, and it is our business now
to trace the main lines of this development. Here
is no necessity to enter into the causes of change;
whether we believe in Natural Selection or Lamarck-
ism, are driven back to Bergson's elan vital, or even
to a complete confession of ignorance, is immaterial as
long as we accept change as a fact Then our task
is merely to trace the change itself in its course and
60 ANIMAL INDIVIDUALITY [OH.
expose what to the best of our belief are the main
steps it has taken.
Every organism has a general scheme of archi-
tecture which can be seen behind the mass of minor
adaptive details. It is easy for instance to recog-
nize the vertebrate plan in such different-looking
creatures as a giraffe, a sparrow, and a sunfish, or
the insect plan in butterflies and fleas. With such
a plan to start from, change may work in three main
ways. First, it may run through the variations on
the original plan, without introducing any new com-
plication. The different species of a genus, for
instance, usually differ from each other in this way.
Every one can recognize that polar bear and brown
bear and grizzly bear are all built on the same bear-
plan, though no one can say that one is better, more
differentiated, than another. In the second way the
original type of plan is retained, but complications
are introduced which imply true differentiation of
parts and division of labour ; such parts have never
been free and independent, so that the division of
labour is very different, in origin especially, from
that of insect communities or our human society,
where the parts themselves begin as independent
individuals. This is not mere change for change's
sake, but change progressive. We may call this
method internal differentiation, implying that all
has taken place within the original unit. An
n] BIOLOGICAL FOUNDATIONS 61
architectural metaphor may help us. Life finds in
the cell the ground-plan for her first mansion — a
one-roomed hut. You may change your one-roomed
plan from round to square, from square to oblong,
and you will not have improved it: but add a
chimney and windows, and at once, though still but
one room, it is something better. Even a church
witli its aisles and nave, transepts and choir has grown
thus by internal differentiation. In essence it must
always be a single room so that the congregation
may see and hear the service; and we realize the
justice with which the Romans used aedes in the
singular to mean a temple.
With equal justice they used the plural for a
house. They had reached the stage of civilization
when a house was no longer a single room, serving
more ends than one at once, and all in turn, but a
collection of rooms, each one different from any old
single-roomed house, all modified in their architecture
from being thus built up into a common whole, but
none the less obviously separate rooms, each in itself
a unit, each somehow comparable with the single
space of the more primitive dwelling. This way, of
joining unit with unit, is the third way with organic
change. Suppose that instead of separating from
each other after each division, the cells remain con-
nected. The result will be a colony of cells each one
like all its fellows. If division of labour sets in later
62 ANIMAL INDIVIDUALITY [CH.
among the cells, they are rendered mutually depen-
dent, and the colony is transformed into a true
individual, which is obviously of a higher order than
the cell. It has attained what may be termed the
second grade of individuality.
This method, for want of a better term, I shall
call aggregate differentiation, to show that the
individual formed by its means consists of an aggre-
gation of smaller individuals. It differs from the
second method in that division of labour, instead
of taking place among the parts of a single unit,
affects whole units or even groups of whole units.
This third method is of special importance for
the evolution of life because those organisms that
have adopted it have found the only satisfactory
solution of that besetting problem — how to become
large. It is of importance for the understanding of
individuality because it gives the clue to many of
the apparent paradoxes of the higher organisms or
Metazoa— why they are built up of units comparable
with free-living Protozoa, why they so often reproduce
by means of a single cell, why the embryo produced
from this single cell so often consists of a number of
almost identical cells among which division of labour
only later sets in.
Now that the animal has separate units to build
with, each with a firm membrane and definite shape
of its own, progress is much more rapid. In the first
n] BIOLOGICAL FOUNDATIONS 63
place, metabolism can be maintained in spite of
increased size, since conducting channels for the food
and waste-products can be constructed.
This would be all but impossible within the limits
of an enlarged single cell, owing to the semi-fluid
nature of its protoplasm; but now since each cell
has a firm outer wall, by joining cell to cell tubes
can be made through which the food and the waste-
products can quickly pass from end to end of the
organism instead of having to work gradually through
by diffusion. At first, as in flatworms, most of the
various systems of the body — the digestive, the
genital, and the excretory — are themselves profusely
branched, but later the whole business of distribution
and collection is taken over by the circulatory system :
this alone is ramified and the others can pursue their
more proper avocations in peace1.
The nervous system is another which can be
much more easily perfected in an individual of the
second grade. To perform complicated actions which
1 There is in many protozoa a form of circulation known as
cyclosis, in which the whole inner part of the cell is constantly
revolving. This certainly performs the same general functions for
the organism as does a blood-system, but to have the whole of one's
inside always in motion would render difficult the development of
other systems ; thus a huge single cell with cyclosis would have over-
come the difficulty of metabolism, but would be at a disadvantage in
other ways when compared with a multicellular organism of the
same size.
64 ANIMAL INDIVIDUALITY [OH.
shall be appropriate to the circumstances, there must
exist a nervous mechanism consisting of various parts,
each part capable of being connected up with every
other part. To evolve such a mechanism from a
homogeneous mass of substance would no doubt be
possible, but to evolve it from a collection of cells
would be certainly easier, for there at the outset
some of the essentials of the finished product — the
separate parts and their discontinuity — would be
already given.
Thus through reaching the second grade of indi-
viduality, life has been able to gain both size and
brain-power for herself. Arid so it comes to pass
that the next steps in her progress have been effected
chiefly by the way of internal differentiation. All
three ways of change were open to her, and all three
have been used in their measure: but the main
difficulty, the difficulty of size, has been removed
from the path, and the second method can now show
its full possibilities. As a matter of fact, the animals
of largest size, of greatest intellect, and of best in-
stinctive powers are all individuals of the second
grade1. At the last, however, when the brain and
sense-organs are sufficiently developed, life has
gained her most elaborate triumphs of individuality
1 In the vegetable kingdom, things are somewhat different, and
the largest plants, the great forest trees, are individuals of a grade
higher again than the second.
n] BIOLOGICAL FOUNDATIONS 65
by a return to the third method, of aggregate
differentiation. How the method is now modified
owing to the possession of a highly-developed brain
by the units with which it works, will be treated of
in Chap. V : every age has known and wondered at
the results it has produced — the communities of bees
and ants, and the societies of man himself.
Enough has been said to give the stranger in
the land a general orientation, and to show him that
Life will guide him to a better view-point than Man
alone. The main outcome of the enquiry has been
to show that living matter at its first appearance
on earth, as the direct results of its material com-
position, could only express itself in the form of cells
—rounded masses, microscopically small, each bound,
after attaining a limit of size, to divide into two
equal halves. Decreed thus by necessity at the outset,
these cells are used ever afterwards as the words out
of which all life's poems are fashioned. All living
things are made of cells and of structures built by
cells : all living action is reducible to cell-action.
And it was no hyperbole to say that the English
Nation is the direct descendant of an ancestor
which throughout its life remained a single cell.
The cell was not from the outset an individual:
but by its fixed limits of size, its defined shape, and
its power of assimilation (by the combination of
these properties, be it understood, and not by any
H. 5
66 ANIMAL INDIVIDUALITY [OH.
one of them taken singly) it was the first thing
evolved to which individuality could adhere. It was
like Benjamin Franklin's kite, bringing lightning
down from heaven, but it did more than that, for it
provided a permanent resting-place on earth where
individuality could stay, could gather strength and
develop upwards. For this reason it is right to speak
of the cell as the foundation of animal individuality.
How in later times the relation of the cell to the
individual is modified must be left for the present
on one side (see pp. 137, 150): we must now retrace
our footsteps and see how others have defined the
animal individual.
CHAPTER III
SOME OTHER DEFINITIONS OF ANIMAL INDIVIDUALITY
FROM time to time various definitions of in-
dividuality have been given by zoologists. Most
of them are framed with little reference to the
philosophical idea of individuality, and the result
has often been that the term individual as defined
by them, though applicable to some reality of
zoology, can no longer be used without absurdities
in its more popular but more correct and more
original sense.
m] OTHER DEFINITIONS 67
One of the most widespread definitions considers
the individual as "the total product of a single
impregnated ovum " (8 a, p. 59), that is to say as the
sum of the forms which appear between one sexual
act and the next. This would make all the polyps
in a colony of hydroids, all the separate polyps
budded off by a fresh-water hydra, all the summer
generations of the aphis, together constitute but
a single individual. Of recent years it has not found
so much favour, but Calkins (2) has urged that it
should apply to protozoa, declaring that all the
separate cells arising by continued division from
a single parent between one sexual act (conjugation)
and the next, should be considered as one individual,
no less than the cells of a metazoan like man,
which too arise by continued division from a single
parent, the ovum, and remain connected to form his
body.
Of the various facts which make the hypothesis
untenable, the chief are concerned with the artificial
or accidental production of two or more co-existent
organisms from a single ovum.
In most animals each single fertilized egg gives
rise to a single embryo and this to a single adult
organism: but in some, where this is the normal
rule, more than one embryo may be accidentally or
artificially formed from one egg, and in others this
multiplicity is the usual course of events, even
5—2
68 ANIMAL INDIVIDUALITY [OH.
though most of their relations may grow up in the
ordinary humdrum way — " one egg, one adult."
Aberrations may occur even in man : there can
be very little doubt that identical twins1 (to leave
all double monsters out of account) arise from the
two cells produced by the first division of a single
fertilized ovum, which have accidentally been torn
apart instead of staying united.
A very interesting variation on this is seen in
the nine-banded armadillo (Dasypus novem-cinctns)
which regularly produces "identical quadruplets" (14).
Most mammals give birth to several young at one
time, but usually each grows up from a separate and
separately fertilized ovum and each is enclosed in its
own set of embryonic membranes. The armadillo's
brood, however, like the identical twins in man, has
only a single chorionic membrane, and the four re-
semble each other minutely. Always of the same sex,
their measurements are identical ; even the number
of plates in their armour is constant to less than 1
per cent., though the range of variation from brood
to brood may be 5 per cent, and more2.
1 It is well known that there are two kinds of twins: identical
twins, always of the same sex and almost indistinguishable from each
other, and ordinary twins, which may be of opposite sexes, do not
resemble each other more closely than brothers of different ages, and
like them arise from the fertilization of two separate ova by two
separate spermatozoa.
2 It is an interesting fact that the four twins fall naturally into
in] OTHER DEFINITIONS 69
Then comes Experiment and confirms our con-
clusions of observation. The egg when it develops
outside the body of its parent (the rule with most
of the lower animals) is at the mercy of the experi-
menter. After it has divided into two halves, these
two blastomeres (as the cells produced by the sub-
division of the egg are called) can be separated
either mechanically or by chemical means. In the
majority of animals where this is possible, the half-
blastomere, that identical mass of substance which
without man's intervention would have formed half
the body of the adult, develops, owing to the mere
accident of separation from its sister, into a whole
body. Even with such a highly organized creature
as the newt this has been accomplished.
The experiment may be carried still further.
A whole jelly-fish (Liriope) may grow up from a
quarter-blastomere, and in sea-urchins a single one
of the first 8, 16, or even of the first 32 blastomeres
two pairs, the resemblance between the members of which is still
more close than that between the four taken together. This taken
together with the fact that the members of the pairs are always
adjacent seems to show that the fertilized egg divided into two
halves, A and B, which did not remain united. Then A divided into
al and a2, B into 61 and 62, and these again parted company.
These four cells gave rise to four separate embryos, al and a2
forming one pair, II and 62 the other. Thus one pair is descended
from A, the other from B, and the closer resemblance of the members
of a pair is explained by closer blood-relationship.
70 ANIMAL INDIVIDUALITY [OH.
will make a gallant attempt to develop into a
normal whole ; and, though it does not succeed,
its death seems due to mere minuteness, lack of
size, rather than to lack of that internal machinery
which produces the complex adult from the simple
egg.
These facts are a reductio ad dbsurdum of the
theory. It is difficult to consider the two or more
experimentally produced sea-urchins or newts as
constituting a single individual ; the four armadilloes
with their one individuality raise more than a doubt ;
and with the occasional and accidental production of
true twins in man comes finality. If anything is an
individual on this earth, that surely is man ; and yet
we are asked to believe that though the most of us
are true individuals, yet here and there some man
who lives and moves and has his being like the rest
is none, that he must make shift to share an in-
dividuality with another man simply because the
couple happen to be descended from one fertilized
egg instead of two. In himself a twin is like any
other man ; to say that one is an individual while the
other is not, takes all meaning from the word.
The idea rests partly on a misapprehension of the
sexual process, partly on realities which are of some
zoological importance but have no true bearing on
the idea of individuality.
Until very recent times the sexual process, the
in] OTHER DEFINITIONS 71
so-called "act of fertilization/' was looked on as some-
thing which had to be repeated at regular intervals
to keep the race going. Somehow it communicated
to the organism a mysterious force, which sooner or
later dying down must be renewed by repetition of
the act.
This is by no means a true view of sexuality. To
start with, one large group of organisms, the Bacteria,
seem not to possess it at all, while here and there in
higher groups it has been lost ; the American water-
weed (Elodea) for instance, that pest which at one
time choked half the waterways of England, started
its career in this country by being accidentally
imported with American timber, and in all its
subsequent development has never been known to
form seed.
Lower down, near its first appearance, it is not
connected with reproduction at all, as in the Ciliates
among the protozoa. Hereto it is not a necessary
part of the life-history; Woodruff (20) has recently
shown that these animals, which reproduce by fission,
may be bred through an indefinite number of genera-
tions without conjugation. Enriques, on the other
hand (7), has shown that a ciliate which has just
conjugated, or in other words received a part of the
nucleus of another and joined it with its own, may,
before dividing at all, and with this very nucleus just
formed by sexual fusion, immediately repeat the
72 ANIMAL INDIVIDUALITY [OH.
process. These observations show that the sexual act
stood originally in no relation to the life of the cell,
or of the multicellular organism, or of the race, so
that any conclusions with regard to individuality
based on the periodical recurrence of sexual fusion
cannot be fundamentally true.
But though the theory cannot be upheld in its
entirety, yet some of the facts upon which it is founded
are of considerable interest not only generally but
also in reference to individuality.
To start with, the upholders of this theory, such as
Professor T. H. Huxley (8 a), base themselves largely
upon the facts of metamorphosis, that sudden change,
from the grub to the fly, from the tadpole to the frog,
that occurs at a definite point in the life of so many
animals. What is perhaps the most remarkable
example of metamorphosis, that of the Pilidium into
the Nemertine, he does not mention, since it was only
established some three years later, but as it illustrates
his contentions better than any of his own examples,
it may be given here.
Many of the nemertines — salt-water worms with
long cord-like bodies — lay eggs each of which develops
into a transparent free-swimming creature, very
unlike its parent, and called Pilidium from its re-
semblance to a little hat (Fig. 5). The hat is provided
with ear-flaps, and between the flaps there is a mouth
leading up into a capacious stomach.
in] OTHER DEFINITIONS 73
That is its structure when young : at the close of
n
Fig. 5. Diagram of a Pilidium with young Nemertine enclosed.
&, band of special long cilia; e, envelope enclosing the worm ;
w, mouth ; n, the young worm ; s, stomach. (Magnified.)
its life, however, it is seen to contain a darker some-
thing within itself, and this something on closer
74 ANIMAL INDIVIDUALITY [CH.
inspection turns out to be a young nemertine worm,
wriggling actively inside a hollow sac which intervenes
between it and the tissues of the Pilidium. This is
strange ; but stranger still, the young worm contains
within itself the stomach that was the Pilidium's, so
that when the Pilidium feeds, the food passes through
its mouth into the stomach which is now the worm's.
The origin of the worm is equally curious : at a
certain stage in the growth of the Pilidium, five little
pockets appear on its outer surface, arranged in a
ring a little above the brim of the hat. The pockets
deepen, and their outer openings get narrower and
narrower, at length becoming quite "sewn up," so that
there are now five closed bags under the skin. These
bags flatten and then extend round the stomach of
the Pilidium in every direction, laterally as well as
up and down ; they thus meet each other, and the
walls which are in contact then disappear, so that all
their separate cavities join up into one. There is
now beneath the skin an outer shell, then a cavity,
and then an inner shell which surrounds the Pilidium's
stomach. This inner of the two shells or sacs becomes
thickened, undergoes various transformations, and at
last gives rise to the body wall and many other organs
of the young worm, while the outer sac is merely a
temporary protective envelope. The worm at length
wriggles so violently as to break through this envelope
and the skin of the Pilidium, meanwhile tearing the
in] OTHER DEFINITIONS 75
gullet where it passes from the body of the Pilidium
into its own. The worm goes on its way rejoicing,
and grows up into an adult nemertine ; while the
Pilidium still swims about, though stomachless, for a
time, but perishes at the last.
A perfect gradation in abruptness of metamor-
phosis can be traced up to this extreme condition.
Often, as in man, development proceeds gradually — a
slow transition through continual change. In others,
as in the frog, there is one period when a sudden
alteration of habit and structure takes place; the
tadpole, we say, undergoes a metamorphosis and is
made a frog. But though there is radical rearrange-
ment, nothing is discarded. In the butterfly there is
a more violent metamorphosis, and also a part of the
earlier form, its outer skin, is discarded during the
change. Finally in the Pilidium not merely the skin
but nearly the whole of the larva is rejected at the
metamorphosis.
From this, Prof. Huxley then says, it is but one
step for the larva to keep all its essential organs when
it parted company with the adult form ; the one would
be formed by the other after the fashion of a bud, and
from this on to the establishment of colonies like those
of the hydroid polyps would be but one step more.
Then we should have a perfect transition : the animal
as it develops is represented first by a succession of
forms, each one turning into the one that comes after,
76 ANIMAL INDIVIDUALITY [OH.
but then first a part and finally a whole of one of the
forms comes to have a separate existence in space
simultaneously with one of the later forms. So, he
argues, since the tadpole and the frog can rightly be
called mere forms or phases of the same individual,
then the Pilidium and the Nemertine, and then all the
polyps in the hydroid colony1, are but such forms
too.
As a matter of fact, this gradation does not seem
to exist in nature ; but even if it did it would not be
convincing. It is often forgotten that the most perfect
quantitative gradation from one condition to another
is no guarantee that the two conditions shall not be
qualitatively different. To take the simplest example,
when the chemical substance denoted by the symbol
H20 is heated, a definite addition to the rate of motion
of its molecules is made for each degree of tempera-
ture through which it is heated. This quantitative
addition, however, has a qualitative result: with
continued heating the substance passes from the
solid state into the liquid, and from that into the
gaseous, turning from ice to water, from water to
steam. There is a similar gradual transition in life
from the mere aggregate to the higher-grade in-
dividual (Chap. IV).
Here, however, there seems to be no such series.
1 The examples actually used by him are the Salpae and the
Aphides.
in] OTHER DEFINITIONS 77
All goes well up to the Pilidium, but then comes the
gap. There is no case known where two complete
individuals are formed as the result of metamorphosis.
In reality, the detachment of the Pilidium skin from
the young worm is not an attempt at reproduction at
all, but is due to something very different. This
something is the incompleteness of adaptability in
protoplasm, and since the subject will concern us
again later (p. 132 et seqq.) it may be investigated here.
The whole raison d'etre of a metamorphosis is the
restriction of the animal to one environment in one
period of its life, to another and a wholly different
environment in another period. Different environ-
ments require different structures ; and the metamor-
phosis is the time when the old structures are destroyed.
When the tadpole, for instance, suffers a land-change,
gills and tail must vanish. They do not, like the
skeleton of the gills, become converted, after con-
siderable remodelling, into structures of the adult,
nor like the caterpillar's outer skin, are they bodily
cast off: they are absorbed, they shrink and their
contents are drawn into the body of the young frog
for future use, as the yolk-sac and its contents are
drawn into the body of the unhatched chick.
The tadpole is so well adapted to the water, the
frog so well adapted to the land, that certain organs
cannot be used, however remodelled, for life on both.
They cease to exist as such ; it is only the materials
78 ANIMAL INDIVIDUALITY [CH.
of which they are composed, not the living organs
themselves, which the animal uses for its further
development.
There is a wide possibility of change inherent in
all living substance, but after a certain specialization
of cell or organ is reached, it becomes impossible to
remodel it to perform another totally different func-
tion. I say impossible : it would perhaps be safer to
say that the difficulty of remodelling becomes so great
that the simplest way, and so the least wasteful of
energy for the organism, is to destroy the old structure,
degrading it to the level of mere food-material, and
then to build up the new from its very beginnings.
An extraordinary example of this is found in the
development of the higher insects. Practically every
organ of the body in a larval form like the caterpillar
becomes broken down, chiefly by the action of
phagocytes, into lumps and masses of dead proteid
substances.
A boy known by repute to the writer once
expressed surprise that there were any organs inside
caterpillars : " I thought," said he, " that they were all
just skin and squash." This would be a very accurate
description of their condition during the metamor-
phosis, were it not that embedded in the squash at
intervals there lie little patches of living tissue.
These so-called imagined discs are formed of un-
specialized cells ; they grow, unite with each other,
in] OTHER DEFINITIONS 79
and develop gradually into the structures of the
perfect insect.
In the Pilidium, it seems, the young worm finds
that less energy is wasted in feeding on its own
account than in attacking the larval tissues and
converting them into readily assimilable food-stuffs.
That part of the individual, therefore, which has been
so specialized for a free-swimming life as to defy
remodelling for worm-purposes, is discarded alto-
gether instead of being absorbed1.
As with cells and organs, so with human beings :
it is rare that the skilled workman can change his
trade. When he is too specialized it may be easier
to give him notice and train a new apprentice than
to go through the pain and grief of the change from
fixed habits.
The remains of the Pilidium then represent merely
a part of the Nemertine individual which is discarded
as being no longer useful : the history of the process
shows that it has nothing to do with ordinary asexual
reproduction such as the budding of 'polyps in a
1 In one species of Pilidium (P. recurvatum Fewkes), however, the
young worm does actually absorb the remains of the larva. It is
interesting to note that a precisely similar series can be traced in the
metamorphosis of echinoderms. In the sea-cucumbers the process
is almost entirely one of remodelling, in sea-urchins and most
starfish the young imago is formed apparently as a "bud" and the
rest of the larva is absorbed later, while in some starfish (vide
J. Muller) the larva and the imago part company.
80 ANIMAL INDIVIDUALITY [OH.
hydroid colony, and so, even were the detached
larval part to regenerate a new stomach and become
a separate self-supporting organism (as is not un-
thinkable) we should not be able to draw any
conclusions applicable to colonies produced by
ordinary fission or budding.
There is another reality on which, unconsciously,
the theory is based. In all Metazoa there is, before
and during the sexual process, a shuffling and recom-
bination of the chromosomes of the nucleus — those
bodies which taken together appear to determine the
characteristics of the offspring, or at least those which
mark it off from others of the same species, — whether
it shall be tall or short, fair or dark, chubby or lanky,
tip-tilted or Roman-nosed. More, it was supposed
that this rearrangement only took place during
sexual fusion, and instances were adduced of many
vegetable "sports," or mutations as they are now
often called, so many of which have been enumerated
by De Vries. A plant will often appear showing a
mutation in all its parts, so that the change inducing
the mutation must certainly have affected the single
sexually-produced cell from which the whole plant
has sprung. Once formed, mutations will persist in
cuttings or slips of the parent plant, but will usually
be lost when the sexual chromosome-shuffling is
allowed to take place and offspring are raised from
seed. In such cases then, all the plants that have
in] OTHER DEFINITIONS 81
arisen thus asexually by grafts or slips, from actively
growing parts of the one original parent, all possess,
in the mutation, a common character separating them
from other plants of the same species, and this
common difference persists as long as sexual fusion
does not take place between bits of their proto-
plasm.
Phrases such as " he has a marked individuality,"
or "he is very individual" lead people to suppose
erroneously that one of the chief characters of an
individual is its difference from all others. Then,
seeking for some clue to guide them through the
mazes of animal individuality, they seize upon this
and say that because one stream of protoplasm
exhibits constant differences from other streams, it
is therefore an individual. It then appears that in
many cases these differences only persist from one
sexual act to the next : therefore, say they, the sum
of the forms between two sexual acts must constitute
an individual.
However, even apart from the initial flaw, that
mere difference constitutes individuality, the chain
of argument will not hold, for it is found that not
all mutations are similar to those we have described :
permanent and considerable changes may take place
at any time during the life-cycle, and not in the
sexual act alone. The so-called bud-sports of many
plants are of this nature : from a single bud on a
H. 6
82 ANIMAL INDIVIDUALITY [CH.
normal tree grows out a shoot displaying some new
peculiarity, some mutation which it can transmit to
its descendant shoots. A race of trees with the new
character can thus be raised by grafting, and not
only this, but some bud-sports breed true to seed.
Thus nectarines have repeatedly arisen from peaches,
not only from peach-seed, but also from peach-buds,
and in both cases may subsequently grow true to seed
(4, p. 360).
One last partial justification of the theory is left :
often when more than a single individual life (in our
sense) intervenes between one sexual act and the
next, it happens that these several individuals are
different from each other but appear in a regular
cycle, as in the liver-fluke (p. 23). When this is
so, the forms that intervene between two sexual acts
do in point of fact together constitute an individuality,
one of the type that we have called species-indivi-
dualities. But this coincidence of sexual act and
beginning of a new individuality is only an accident,
philosophically speaking, as our previous discussion
of the sexual process will easily prove (p. 71).
Thus, though we may note as an interesting fact
that the sexual process has at various times and in
various ways become connected with one or another
form of individuality, yet we must recognize that this
connection is not obligatory, that in origin the two
are entirely distinct, and that therefore the one
in] OTHER DEFINITIONS 83
cannot possibly be used as the basis for the definition
of the other.
Another and a very different view is taken by
Le Dan tec (11), who, sticking to etymology, gives
the following definition : " Tindividu vivant est done
un corps qui ne peut 6tre divis^ sans que Tune au
moins des parties resultant de la division perde la
vie." This happens, he says, only when there exists
a nervous system, and one where the nervous elements
are concentrated at certain points to form centres of
control and co-ordination, a process which as its
climax produces the brains of the higher insects and
mammals1. Each nervous centre constitutes then in
some way the nucleus of an individuality and only
animals with highly-centralized nervous systems can
properly be called individuals.
The real error of this view lies far back in its
premises. The definition contains an error of logic.
You may correctly insist on etymology and say that
an individual is something which cannot be divided
without losing its essential quality : but when you
say that the essential quality is life, you are not
talking sense. The essential quality of an individual
is not life but individuality. As a matter of fact, an
1 As a matter of fact there are animals, such as the sea-urchins,
where death results from division of the body and yet is certainly
not caused by any dislocation of nervous centres, for the sea-urchins
have a very feeble and very decentralized nervous system.
6—2
84 ANIMAL INDIVIDUALITY [OH.
individual as defined in this book cannot be cut in
two without its individuality being either lost or
impaired (p. 46) ; and though the loss may be only
temporary it is none the less real.
Le Dantec's idea, however, is not merely based on
error. The centralized nervous system does form the
nucleus, not of any individuality it is true, but of
that special kind of individuality, a personality.
However, since not all brains, but only those
whose mechanism allows some conscious reason and
memory, are the structural tokens of a personality,
and since it is beyond our present power to dis-
criminate between conscious and non-conscious brains
from mere appearance, this structural criterion breaks
down in practice and we are driven to accept be-
haviour as the only accessible touchstone for
personality.
The same is true of individuality. An individual
is not an individual because it arises from the sexual
fusion of two cells, nor yet because it possesses
a certain aggregate of white fibres and grey cells
called a nervous centre. Even were it a fact that
on this earth these two properties were always
associated with individuals, they would still not
afford the proper basis for a philosophic definition of
an individual. They would be mere accidents of the
individual, which would still owe its individuality not
to them, but to the particular way in which it works.
iv] THE SECOND GRADE 85
The essential thing about an organism is its actual
working, the way it directs the current of energy by
which it is continually traversed, and causes it to act
on the external world. The main errors of materialism
on the one hand and of teleology on the other
have resulted from thinking either of substance and
structure alone, the mere tools by which the working
is carried on, or only of the apparent purpose for
which it seems to exist, and not merely of the working
itself. Only on this basis can a definition of individu-
ality be attempted, and it is by neglecting this basis
that many have been led to false conclusions.
CHAPTER IV
THE SECOND GRADE OF INDIVIDUALITY
AND ITS ATTAINMENT
Question : " What's one and one and one and one and one and one
and one and one and one and one ? "
Alice through the Looking -Glass.
Answer (sometimes) :
"Each one almost a Whole, yet all but Parts
They have lost self to form a Greater Whole
Far nobler than its sum of single Parts."
The Green Bayswater.
IN Chapter II it was shown that the very existence
of the first living individual, the cell, was originally
86 ANIMAL INDIVIDUALITY [OH.
determined by the material properties of living sub-
stance. There are large cells and small cells, but,
with few exceptions (see p. 89), it is a very limited
largeness to which even the largest attain. This
limitation, depending as it does upon the surface-
volume ratio, is one of the primitive, original
attributes of the cell ; and to attain size, the cell
must in a way do violence to its nature, somehow
modifying its surface-tension, overcoming its natural
tendency to the spherical, so as to keep its absorptive
organ, the surface layer, large enough to supply the
demands of the inner mass.
Why, however, should the cell not be content to
stay small — what is it to gain from size that it should
strive after it ? One is apt to think of size as a rather
unimportant element in life. With the example of
the field-mouse and the elephant, both built so
closely on the same type, the wren and the albatross,
one comes to think of a model of organization which
can be fitted at will on to whatever bulk of living
matter is desired. Within wide limits this is true, no
doubt, but limits none the less there are.
Many Neo-Darwinians, too, argue that adaptation
is the great reality gained by organisms through
natural selection, and that, therefore, no one species
now alive has preference over any other — for to be
alive both must be adapted to their surroundings.
But to exist and nothing more, to vegetate merely,
iv] THE SECOND GRADE 87
is not the fate of all organisms. There is a higher
and a lower, for some are more independent, more
powerful than others.
It is now that the importance of size is seen ; for
increase of size means increase of independence.
Most of the forces of the outside world act only on
the surface of the organism ; but its own forces spring
from the whole mass of its substance. The energy
necessary for action is let loose by the chemical
breaking-down of the molecules of protoplasm and
by their combination with oxygen. This, in a primi-
tive cell, is a function of all the molecules, and so of
its total bulk. In the higher animals, where loco-
motive power is delegated to the muscles, the relation
still holds good; the three dimensions and so the
shape of the thigh-muscles of a jerboa and a kangaroo
are approximately the same, and so the surface-
volume ratio will hold accurately. If the length of
the kangaroo is ten times that of the jerboa, then the
surface of his thigh-muscles will be a hundred, the
bulk a thousand times as great. Of the outside forces
(all antagonistic or at best passively resistant to the
organism) that of gravity only is proportional to its
mass. If it alone were to be considered, size would
make no difference to the animal's movements — the
weight to be moved would increase proportionately
with the forces that were to move it, since both are
proportional to the mass of the whole.
88 ANIMAL INDIVIDUALITY [CH.
In reality, even if we consider locomotion alone,
the resistance of the medium — air, water, or earth —
in which the creature moves, is equally important
with gravity. Everyone knows how much harder it
is for a thin, loose-built man than for a close-knit,
compact one of equal weight, to make headway in a
gale of wind. That is because the pressure of the
wind is proportional to the surface exposed, and the
thin man, with relatively more surface exposed, has
less muscle with which to drive his body onward.
The home of all primitive life was the water ; and
the resistance of water is immensely greater than that
of air. The disproportion between inner and outer
force is here so great that it is as impossible to think
of any single-celled animal swimming against the
most sluggish river as it is to imagine a butterfly
poised steady in a twenty-knot gale.
Once more we see the importance of the surface-
volume ratio: but what it preaches now is for the
organism in direct contradiction to its earlier lesson.
Then it said, "thus far and no further, on peril of
starvation/' Now it warns, "stay thus small, and be
condemned to continue the sport of the elements."
How is life to escape from this quandary? She
may be content to remain small, like all the present-
day Protozoa. Many of these have attained the most
amazing complexity for their size; but there are
physical limits to the amount of structures that can
iv] THE SECOND GRADE 89
be contained in a small fraction of a cubic millimetre
of substance, and this way has led up a blind alley.
One tribe of plants, the Siphoneae, has made a brave
attempt to gain size while still remaining a single
cell1. A plant of Caulerpa, for instance (one of these
sea- weeds), may have several square feet of surface,
and in spite of being one continuous piece of proto-
plasm with a wall of cellulose round it, is differentiated
into organs resembling in appearance and no doubt
in function the stem, leaves, and roots of higher plants.
Needless to say, it has only been able to attain this
relatively huge bulk by restricting itself to growth in
two dimensions only, and is quite thin and plate-like
throughout.
What possibilities of development lay along this
line we cannot say ; all we know is that actually it
has not led far. The real advance has been made
in a quite different way ; by keeping the cell's
original form and plan, but joining up a number of
1 I am aware that botanists distinguish between cells, which have
one nucleus, and coenocytes, or masses of protoplasm with many
nuclei, such as are found in Caulerpa and other Siphoneae. However,
I am using the word cell in a wide sense, a sense dictated by the
historical or evolutionary point of view, to denote a discrete mass of
protoplasm isolated by natural causes, and if this definition be
allowed, then Caulerpa is simply a single cell which has found out
the way to become large. The number of nuclei in a cell is often
quite unimportant: in the Protozoa one form may have a single
nucleus, while a close relation has several.
90 ANIMAL INDIVIDUALITY [CH.
them together so that each preserves a considerable
measure of independence, and is yet subordinated
to the good of the whole. This resulted in the
metazoan type of structure, where the individual
is built up out of a number of cells instead of one.
As an example of a simple metazoau, we had
better take a primitive sponge. Among sponges,
Clathrina blanca is one of the most primitive. A
graceful vase-like creature, pure white, with a long
stalk of attachment, and a mere fraction of an inch
in length, it obtains its food, like the majority of
sedentary aquatic animals, by producing a current.
A stream of water can easily be demonstrated passing
out of the circular mouth of the vase, and, with a
little more trouble, can be seen to enter by a number
of quite small holes scattered over the walls. The
current is produced by the cells lining the central
cavity (Fig. 6) : these stand side by side like sacks in
a granary, their free upper ends tapering very slightly,
and then truncated at the top. The flat top of each
is surrounded by the most remarkable transparent
cylinder, a mere film of protoplasm, yet beautifully
round, and capable of being drawn in at will, or
protruded till it equals the cell in length. This is
called the cottar, and in the centre of it there springs
from the cell a long vibrating lash or ftagettum, of
uniform thickness throughout, and also capable of
retraction within the body of the cell, ^sually
IV]
THE SECOND GRADE
91
however it is very much in evidence, beating several
times a second, and so producing the current, from
which food is taken up and digested by the collar-
cells. The bases of these cells rest upon a thin
layer of jelly — dead stuff secreted by the living cells,
Fig. 6. Clathrina coriacea, Mont. Two sections of the body-wall.
E, not quite fully expanded ; the collar-cells line the cavity of
the sponge, and show collar and flagellum. F, very much con-
tracted. The collar-cells have withdrawn collar and flagellum,
and are lying in irregular masses behind the layer of immigrated
pore-cells, am.c, amoebocytes ; c, collars of choanocytes (ch.c) ;
d.ep, dermal epithelium ; fl, flagella; p.c, pore-cells; sp.c, spicule-
cells. (Highly magnified.) (From Minchin.)
and serving, like the somewhat similar gelatinous
tissue we shall see in Volvox, for the common support
of the separate cells. On the outside of the jelly is
the dermal layer of flat polygonal cells, fitting
together like a mosaic of tiles. The pores through
which the current enters are perforations in the
92 ANIMAL INDIVIDUALITY [OH.
bodies of cells, of a third kind large and contractile,
each of which stretches drainpipe-wise from the
outer world to the central cavity. Embedded in the
jelly itself are other supporting structures — three-
rayed spicules of carbonate of lime, and through it
wander at will a number of amoeboid cells, having
much the same appearance and functions as our own
white blood-corpuscles, except that from their ranks
are recruited the germ-cells, male and female ; here,
therefore, we have the unusual1 spectacle of the
germ-cells being pressed into the service of the
individual.
Here is obviously a unity, an individual of a
higher order than the cell. Its forms and its functions
both depend as much upon the way the component
cells are arranged as upon their structure ; from an
examination of a single one of its cells, or even one
of every kind of cell, you could deduce very little
about the properties of the ordered whole. That
whole is greater than the sum of its parts ; for the
problem is one of combination, not of mere addition.
In spite of this the cells have preserved a very large
amount of independence, and indeed do most forcibly
present themselves to the mind as bands of beings
like ourselves that have voluntarily enlisted under
some beneficent tyrant of a general. That analogy,
1 But not unique — e.g. in some colonial Ascidians, the germ-cells
of the bud are formed from blood-corpuscles of the parent.
iv] THE SECOND GRADE 93
between cells and men, body and state, has been too
often and too far pressed; its incompleteness is at
once grasped with the realization that no such general
does or can exist for the cell-battalions to obey.
What the bond is that keeps them together, what
the force that orders them — this is still one of the
most mysterious problems of life. We must first
grasp the extent to which minor individualities can
persist within the major — see how that centralized
empire, the body of one of the higher animals, was
in its origin a federation, not a tyranny.
In Clathrina, the cells' independence is largely
realized by mere inspection. The collar-cells only
touch each other with the lower part of their bodies,
and when the sponge contracts, as it does in un-
favourable conditions, they— after drawing in their
collars and flagella out of harm's way — are actually
forced over each other, so that instead of a single
unbroken layer there is an irregular collection of
cells filling up almost the whole of the central cavity.
Whether when the sponge expands again they always
fit themselves in between their former neighbours
cannot well be proved or disproved, but seems at
least unlikely.
The amoeboid cells wander as they please, and
the outer or dermal cells, though to be of use to
the sponge as protective and contractile tissue they
must constitute a single continuous sheet, and so
94 ANIMAL INDIVIDUALITY [OH.
seem merged and lost in the one dermal layer they
form, yet show themselves still independent in per-
forming their further function, the secretion of the
calcareous spicules. As these are required, single
dermal cells break loose from association with their
fellows, wander off into the gelatinous ground-
substance, and there take up position where the new
skeleton is required. Thus, though what they do
only has meaning in regard to the whole, the way
they do it proclaims them as partially independent
beings.
Experiment reveals further lengths of indepen-
dence— shows the cells capable of veritable insub-
ordination. By means of experiment it has been
possible to study the behaviour of the unit parts
after the individuality of the whole has been totally
destroyed. By chopping the sponge up small, wrap-
ping the bits in the finest silk gauze, and squeezing
them, the cells are wrenched from their attachments,
and pass through the meshes either singly or at most
by twos and threes1. By varying the method, one
can procure, instead of a mixture of all the sorts of
cells, a quantity of collar-cells free from all the rest,
and it is their behaviour that concerns us now.
No properly conducted cell, one would have thought,
could wish to survive this forcible severance from the
1 This has been done on various sponges, including Sycon, a not
very distant relation of Clathrina: see Huxley (9).
iv] THE SECOND GRADE 95
whole, the body which we are accustomed to think of
as constituting the basis of the only real individuality
in an animal. These cells, however, are scarcely
inconvenienced. After a short period of shock during
which collar and flagellum are withdrawn, they begin
joining up one with another, forming irregular solid
lumps which, gradually hollowing their central parts,
are soon transformed into hollow perfect spheres,
their walls a single sheet of cells, and the flagella,
now active, beating on the outside. The general
resemblance to Volvox (p. 104) is striking, and is
made more remarkable by the existence of a group
of Protozoa — the collared flagellates or Choano-
flagellata — whose essential structure is identical with
that of the collar-cells ; if one of these artificially-
produced spheres were found in nature, it would
certainly be taken for a colony of Choano-flagellates.
Many of these spheres were kept alive for over a
month, and there is little doubt that if the right food
were found, they could exist indefinitely, though what
would happen with the multiplication of the cells
and the consequent growth of the spheres it is hard
to prophesy. This remains to be tried ; but the
facts as they stand are interesting enough. For
untold generations no collared cells of a sponge have
ever existed except as a subordinate part of a
whole sponge-body ; and yet, if artificially freed
from that "harmonious constellation," they can act
96 ANIMAL INDIVIDUALITY [OH.
independently, can unite into new societies unlike
anything known to exist in free nature, and can
there subsist for no inconsiderable time.
So much for the independence of the cells :
now for their subordination. If, in the experiment
narrated above, all the kinds of cells are allowed to
remain mixed after their mutual attachments have
been broken, we get a result very different from
that obtained with the pure collar-cells. First of
all, the cells, many of which are still actively amoe-
boid, and can be seen crawling over the bottom,
unite with each other into small lumps and balls.
These balls are unlike any organisms known to exist :
for, although all their constituent parts are alive,
they are without any arrangement and cannot execute
any concerted function. Now comes the strange part :
this higgledy-piggledy of cells joined up at random is
able to reorganize itself, to produce order out of chaos.
First of all the collar-cells sort themselves out and
form a central solid mass, the dermal cells migrate to
the exterior and join up into a single dermal layer.
By so doing (though they still resemble no known
organism), they have laid down the ground-plan of
the sponge, for it is of the essence of sponges to
consist of these two layers in this position. The
subsequent changes are changes of detail ; cells of the
outer layer detach themselves and form the spicules
between the two layers. Then the inner mass hollows
iv] THE SECOND GRADE 97
itself out, and the collar-cells (till now quiescent, with
collar and flagellum withdrawn) arrange themselves
in a single layer round the cavity, and become active
once more. Finally an osculum and pores are de-
veloped and the random collection of cells (though
by processes not seen in normal development) has
become an actual sponge, living and functioning,
similar in every way to one that has grown up from
the egg.
Of the two experiments, the first is the more
surprising, the second the more mysterious. In the
first, a new form of life is produced — something-
capable of living, that is, and yet in its structure
unlike any known animal : but, given the large
degree of independence possessed by the cells, the
rest follows naturally. In the second, however, there
seems to be a strange organizing power superior in
kind to the powers of the cells themselves — an idea
of the whole, informing the parts. Again the image
of a general directing his army, even of an architect
arranging his materials, springs to the mind : but
again, where is the general, where the architect?
There is no possibility of anything thus extraneous
existing in the normal sponge, still less in the
little balls, composed as they are of random cells
in random grouping. However, the nature of this
directive power we must leave for later consideration
(p. 146). Here it suffices to have shown that it exists.
H. 7
98 ANIMAL INDIVIDUALITY [CH.
So far the analysis of the simple sponge individual
has shown it to be composed of definite, separate
cells. These in the normal animal have considerable
freedom and independence, both structurally and
functionally. Under the artificial conditions of ex-
periment, this independence is shown to be very
large, inasmuch as one kind of cell at least can live
alone, leading a strange new life, when separated
from the rest of the body. Though the whole sponge
is a true individual, composed of harmonious parts,
yet those parts can themselves behave as harmonious
wholes. So far, their independence is merely stated
and proved ; by their history it can be more or less
explained, for various converging testimonies all
point to one conclusion, that Sponges are descended
from a particular group of Protozoa, and that there-
fore every cell now forming part of a sponge's body
is derived by an unbroken chain of cell-division
(interspersed of course throughout with sexual cell-
fusion) from cells which existed as free-living and
independent individuals.
On the other hand there does exist a sponge-
individuality higher than that of the cells : to start
with, in the normal sponge all these cells are working
together for a common end, so that every part helps
every other part ; and in the second place, the plan
of this higher individuality somehow permeates all
the cells, so that from any group of all the kinds of
iv] THE SECOND GRADE 99
them taken at random a whole new individual will
organize itself.
After this examination of such a compound in-
dividual, we must now turn and trace the method by
which this second grade of individuality has been
built up, the method by which the Metazoa have
evolved from Protozoa. The step from first to second
grade is one of the two or three most important in
the whole history of life; yet it has taken place
successfully on several different lines, and unsuccessful
attempts are many.
Among the Protozoa, as among almost all other
groups of animals, many species live in colonies —
using the word colony to mean a collection of
organisms all similar to each other, and all united
either by living substance or by some framework that
the living substance has secreted.
Such colonies are not higher individuals in any
sense of the word, but it cannot be denied that
they already possess certain properties on which the
higher individuality can be grounded. A colony,
besides possessing a characteristic shape, forms a
single whole, separate from all other similar wholes ;
this separateness, as has been seen, is a necessary basis
for the exclusively or almost exclusively physical
individuality of the lower organisms. As regards
function, however, the members of the colony often
retain as perfect an independence as they would have
7—2
100 AXIMAL INDIVIDUALITY [CH.
if living solitary. Colonial life in such species (which
are always sedentary), appears to be merely a device
for making the fullest use of a place with g-ood food-
supply. Such spots are few and far between, and are
discovered by rare individuals only ; thus it is of
advantage to retain the descendants of these favoured
few bound together there in colonies rather than
send them oft' at once into the world with more
chances of failure than of success.
In other colonies, function is not so diffuse, and
there is a function of the whole which is more than,
and sometimes quite different from, the sum of the
separate functions of the parts. Even in sedentary
species this can sometimes be seen ; in Zoothainuium,
a colonial bell-animalcule, for instance, a touch on a
single one of the animals composing the colony causes
the whole colony to retract out of harm's way. This
general contraction, common to a number of in-
dividuals, though by no means a necessary result of
colonial life, could obviously not occur if the in-
dividuals were living separately, however closely
they were crowded side by side. But it is in free-
swimming colonies that the unity of common function
is most pronounced- To take the simplest possible
example, imagine two actively-swimming protozoa of
the same species joined together by whatever means
you please. If free, each would have a similar motion
to the other, but both would be independent When
iv] THE SECOND GRADE 101
they are joined, however, the motion of the couple is
no longer similar to the motion of its two components.
Mathematically it is the resultant of their two motions,
and as such depends on the way in which the two
individuals are attached to each other. If the action
of their locomotor organs is not fixed and invariable,
it will also depend on the way in which these are
used by the two individuals.
Hence for the couple to move, it is essential that
the motions of its two parts shall not neutralize each
other, but that they shall be co-ordinated to give a
resultant motion useful to the whole couple.
Then there is the resistance of the water to be
considered, w that before a colonial organism can
move effectively its parts will have to acquire a
shape, an arrangement, and a mode of action,
differing from those which had served them perfectly
when they were independent beings.
The further step necessary before the colony can
with full right be called an individual is the differ-
entiation of its members so that they perform different
functions. As with the primitive homogeneous lump
of protoplasm (p. 57) so with the "homogeneous"
c<>l<»iiv <>f similar members: both are on the wav
j
to acquiring an individuality for themselves, both
exhibit features which are the necessary foundations
of that individuality, but neither can with justice
be said tn jn»sess it.
102 ANIMAL INDIVIDUALITY [OH.
Illustrating these theoretical points, there exist
for us, among various other examples, the members
of the family Volvocidae, — an old but well-tried
object-lesson. These organisms, claimed by botanist
and zoologist alike, are members of the Flagellata,
unicellular organisms marked off by possessing long
whip-lashes or flagella with which they swim. The
Volvocidae seem to be a perfectly natural family.
They are all free-swimming; they are all colonial,
with a framework of transparent jelly common to the
colony ; they all possess chlorophyll, nourishing them-
selves after the fashion of plants ; and they all have
two flagella, a single " eye-spot " and other morpho-
logical characters. There can thus be little doubt
that they are all descended from a single ancestor
who combined these common characters in his person.
The different forms vary very much, however, in
the shape and size of the colonies, in the specializa-
tion of the sexual elements, and in the degree of
individuation of the colonies.
At the base of the series stands Gonium — sixteen
precisely similar flagellate cells embedded in firm
transparent jelly, joined in definite arrangement to
form a flat disc (Fig. 7). The colony thus constituted
lives and prospers, nourishes itself, and grows till comes
the time for reproduction. Then each cell of the
sixteen divides — once, twice, thrice, and four times—
into sixteen little ones. Each of the sixteen groups
IV]
THE SECOND GRADE
103
Fig. 7. Gonium. A, a species containing 16 cells embedded in a flat
' plate of gelatinous substance. B— F, another species, containing
4 cells. J3, C, adult colonies, seen from the top and side re-
spectively. In D one, in E two, and in F all four cells have
divided into four. The four groups of four cells in F will shortly
separate and become independent daughter-colonies. (Highly
magnified.) (From West.)
104 ANIMAL INDIVIDUALITY [OH.
of sixteen breaks away from the rest, arranges its
parts in the familiar way, and constitutes itself a
minute but perfect new colony1.
Among all the other members of the family except
Vol vox, the asexual reproduction (with which alone we
need here be concerned) is accomplished in a similar
way — each cell takes upon itself to reproduce a whole
new colony. They are colonies and nothing more —
their members have united together because of certain
benefits resulting from mere aggregation, but are not
in any way interdependent, so that the wholes are
scarcely more than the sum of their parts.
Though, as we have said, Volvox is obviously
related to Gonium and the others, it is separated
from them by somewhat of a gap.
In the first place, it contains, instead of sixteen or
even sixty-four cells, a vast number, mounting up in
some species to twenty thousand (see frontispiece).
All these cells are inter-connected by fine strands of
protoplasm passing through their party- walls2 and
they are arranged in a single layer on the outside of
a sphere whose inner parts are filled with a very fluid
jelly, so that the Vol vox-colony has what we may call
an internal medium of its own. Finally, and this is
1 Some species of Gonium, such as that represented in Fig. 7, are
even simpler, being formed of but four cells.
2 Though these connections have not been described for other
members of the family, it is possible that they have been overlooked.
iv] THE SECOND GRADE 105
where Volvox has made the great advance, the cells
are not all alike. Most are of the type already seen
in Gonium and characteristic of the family ; these row
the colony through the water, steer it, and feed it.
Amongst them, in the hinder half of the sphere,
are larger cells, lacking flagella and eye-spot, and
connected by very numerous strands with their neigh-
bours,
"Their oarsmen-brothers, by whose toil, safe fed
And guarded safe, they live a charmed life
Within their latticed crystal, peaceably."
And what do they do in return ? Now is discovered
the skeleton in the flagellated cells' cupboard— they
cannot reproduce the colony. They are sterile, and
must leave reproduction to the big lazy-seeming cells
who are only lazy, however, because they must store
up food-materials to start the new colony fairly on its
way. They grow and grow, bulge inwards, and finally
come to float free in the centre space, where they still
grow, meanwhile dividing up into a number of cells.
In the end, they become perfect miniature colonies,
burst out of their parent and swim happily away.
Volvox is thus a real individual ; of the two kinds
of cells each has given up something the better to
fulfil its own special duty. There is division of
labour, and, from the point of view of the species,
each kind is meaningless apart from the other.
The division of labour in Volvox is that usually
106 ANIMAL INDIVIDUALITY [CH.
first seen in compound individuals — between the re-
productive functions on the one side and all the rest
on the other. In other words, one sort of cell is
concerned entirely with the species, the other entirely
with the separate individuals of which the species
consists ; to use the current phraseology, the one sort
is germinal, the other somatic. The word somatic
opens up another view : Volvox is the first organism
which, in the ordinary sense of the word, has a mortal
body. Its substance is not passed on unimpaired
from individual to individual, but with each act of
generation the major part must die, sacrificed for the
greater efficiency of the race.
In Volvox, this body consists of but one sort of
cell : in all the organisms usually known as Metazoa
there are at least two sorts, if not more. Besides the
division of labour between germ and soma, there is
developed another in the soma itself, at the first
between protective and nutritive cells, the one form-
ing an outer covering round the other, which in its
turn surrounds an internal cavity. But even if Volvox
only possesses species-individuality, the individuality
is none the less real ; and the fact that in the family
Volvocidae we can positively affirm that the step from
an aggregate to a higher individual has actually taken
place, is one of the most important in biology.
This, however, is not the only way in which the
second grade can or has been reached. It is quite
iv] THE SECOND GRADE 107
possible that division of labour should set in at the
very beginning, and that no such thing as a colony,
using the word in its usual sense as a number of
equivalent individuals all derived from a single parent
and still connected together, should ever have existed.
The best examples of animals with such a history
are the Catenata, a small group, all parasites of certain
marine worms, discovered by Dogiel (6) only four
years ago, and containing but* one known genus,
Haplozoon. The structure of the most primitive
member of the group is simplicity itself (Fig. 9, e).
It is a single row of cells, one end fixed to the wall of
the worm's gut, the other sticking out into the gut-
cavity. The cells, however, are by no means similar
among themselves. The first one takes over all the
business of attachment, and most of the nutrition.
Actively movable, it possesses at its anterior end a
piercing spine and a bundle of delicate protoplasmic
-threads or pseudopodia, which insinuate themselves far
up between the cells lining the host's digestive tube,
and serve the double purpose of holding the parasite
firm and of sucking up the juices of the neighbouring
tissue. From its posterior end this head-cell is con-
tinually dividing off new cells, which remain attached
to each other in series, up to some seven or eight.
The hinder cells of the series gradually become filled
with particles of reserve food, analogous to the yolk
granules in an egg, and finally lose their connection
108
ANIMAL INDIVIDUALITY
[CH.
with the rest, dropping off into the digestive cavity
and passing thence to the outer world. Attempts to
Fig. 8. Haplozoon macrostylum, x 300, showing the greatest com-
-plexity reached by the Catenata. Only the cell-outlines are
drawn, /i, head-cell with stylet and pseudopodia. A body-cell is
being divided off from it posteriorly. (After Dogiel, slightly
modified.)
rear them further have not succeeded, but there can
iv] THE SECOND GRADE 109
be no doubt that their function is reproductive,
designed to spread the race to other hosts.
That is the simplest form: thence to the most
complex an interesting series may be traced, through
species where a few of the hinder cells divide in such
a way that the animal's posterior end is a plate, not a
mere row, of cells, then up to others where this state
of things begins much earlier, so that the plate is
broadly wedge-shaped, and finally to forms where the
hinder cells divide in all three directions of space, and
the posterior end is large and club-shaped, several
layers in thickness (Fig. 8). In the front half of the
body, little openings exist between cell and cell, which
serve to pass food-substances down from the " head "
into the other cells. When these are full-fed, they
close themselves off from their neighbours and pre-
pare themselves for their reproductive destiny.
The ancestry of these curious creatures is almost
certainly to be sought in another group of plant-like
unicellular flagellates, the Peridineae. These are two
forms which serve to bridge the gap— a large one—
between the active free Peridineae and the parasitic
multicellular Haplozoon.
The first, Gymnodinium pulvisculus (Fig. 9, a), is
also a parasite but an external one: it is found at-
tached to the skin of various pelagic creatures by a
stalk or bundle of sucking pseudopodia like those of
Haplozoon. So it thrives till it is full grown : then,
110 ANIMAL INDIVIDUALITY [OH.
breaking off from its stalk, it divides up into a large
number of little cells each of which develops two
flagella, takes on the form characteristic of the
free-swimming Peridineae, and is oft* to infest new
hosts. Here, it will be seen, the same cell devotes
itself at one period to nutrition and at another to
dispersal.
In Blastodinium mycetoides (Fig. 9, 6), these two
functions are carried on by different structural units :
the full-fed cell does not break off from the stalk that
nourishes it, but divides transversely into two halves
which become separated by a membrane. The one
that is no longer attached to the stalk at once begins
dividing up to form little flagellates, while the other
goes on feeding, grows to full size again, and cuts off
a second reproductive cell.
Now imagine the reproductive cells to remain
organically connected with the stalk-cell and to be
nourished by it for some time after they have been
divided off, and you have in essentials a simple species
of Haplozoon (Fig. 9, c — e).
The Catenata and Volvox are thus similar in
being multicellular organisms with unified function
and with division of labour among their parts ; but
their origin is very different.
In the making of Volvox, community-life — mere
aggregation — came first, division of labour last. In
Haplozoon's history, division of labour existed before
IV]
THE SECOND GRADE
111
any trace of communal existence, and only later was
one cell built up upon another into an individual of
a higher order.
(a) (b) (c) (d) (e)
Fig. 9. Diagram to show the probable evolution of the Catenata.
(a) Gymnodinium pulvisculus, during its nutritive phase.
(b) Blastodinium mycetoides. A nutritive cell remains per-
manently attached to the host, and repeatedly divides
off reproductive cells from itself,
(c) — (e) Haplozoon lineare. h, head-cell.
(c) One-cell stage, resembling (a).
(d) Two-cell stage, resembling (b) except that the two
cells adhere to each other.
(e) Adult, with reproductive cells about to be de-
tached posteriorly.
[Somatic nuclei black ; germinal nuclei white ; mixed nuclei
stippled.] (Modified from Dogiel.)
To take parallel cases in a different grade of
individuality, the simpler Volvocidae closely resemble
112 ANIMAL INDIVIDUALITY [OH.
many low human races among which every family
exercises all the ordinary arts and crafts, and where
society, in spite often of strong communal life, can
therefore not rise above the dead level conditioned
by the impossibility of doing all things at once and
doing them well. Curious and interesting it is that
these same peoples if taught, can generally learn, and
learn quickly and well, many arts and industries
before undreamt of among them. The capability was
there, but they had not learnt how to use it : only
by sacrificing some of their multifarious functions
is it humanly possible to advance in the rest, and so
to raise society. As with men, so with cells — a
jack-of-all-trades cannot advance in any, and the
same lesson of sacrifice has to be learnt before the
colony can become an individual organism.
A human illustration for the methods of Haplozoon
may also be found, or at least imagined. Imagine
then a man inflamed with the desire to spread among
a benighted race some gospel of good tidings. Poor,
he prints the books himself ; then comes the question
of sending them forth. It is obviously impossible
for a single man to do one and the other simul-
taneously. If he goes out to distribute them himself,
the printing will be at a standstill while he is away.
If, however, he can obtain volunteers to distribute
the books, he himself can stay behind and pull off
impressions all the time while a new man goes off
iv] THE SECOND GRADE 113
with each consignment. Suppose further that while
printing he can instruct the distributors in such a
way that they will later be able to do their work
more soundly, then there will be collected a crowd
of embryo distributors at headquarters, from which
the fully-trained ones will from time to time depart.
In the first stage the business is like Gymnodinium
pulvisculus: then like Blastodinium, and at the last
like Haplozoon : the division of labour has come as
the first forerunner of the higher development, and
this it has done because in both cases there are two
special functions to perform which cannot be per-
formed simultaneously by a single individual.
The existence of two mutually exclusive necessities
is thus the origin of this type of higher individual :
at first the single cell performs them both, but at
the expense of not feeding while it is reproducing, not
reproducing while it is feeding. Again the sacrifice
by a part leads to improvement for the whole ; the
great fact once discovered that of two cells one can
feed for both, the other reproduce for both, and the
later steps follow almost as a matter of course.
It is to be remarked that for the two functions
of nutrition and reproduction thus to clash with one
another, it must needs be that the organism can only
thrive in a very special and a very limited environ-
ment. An individuality like that of the Catenata is
therefore found chiefly among parasites, which exist
H. 8
114 ANIMAL INDIVIDUALITY [OH.
in just such an environment; but in the outer world
the conditions are rarely narrow and rigorous enough
to call forth such adaptations1.
It was the other method, aggregation of similar
units and subsequent division of labour among them,
that opened to life the full resources of the second
grade of individuality. In some colony like Volvox
there once lay hidden the secret of the body and
mind of man.
CHAPTER V
THE LATER PROGRESS OF INDIVIDUALITY
" It is provided in the essence of things that from any fruition of
success, no matter what, shall come forth something to make a
greater struggle necessary." WALT WHITMAN.
EVERY human being who has passed through the
moral struggle will testify to the truth of these,
Walt Whitman's words, in their own experience :
the biologist will witness that they symbolize as
real a truth in the history of life. Life can never
be in equilibrium. Given the two well-established
facts, that living substance can vary, and that living
1 To mention two examples, there is the strobila with its ephyrae,
and the Syllids producing their special (epitokous) male and female
forms hy division.
v] LATER PROGRESS 115
things if left to themselves would multiply in rapid
geometrical ratio, then change in the status quo is
inevitable. A state of equilibrium may for a time
exist, but every balanced organism is as it were
pressing against every other, and a change in one
means a rearrangement of them all.
The correlated evolution of weapons of offence
and defence in naval warfare is closely similar, though
simpler far. The leaden plum-puddings were not un-
fairly matched against the wooden walls of Nelson's
day. Halfway through the century, when guns had
doubled and trebled their projectile capacity, up
sprang the "Merrimac" and the "Monitor," secure in
their iron breast-plates ; and so the duel has gone
on, till now, though our guns can hurl a third of
a ton of sharp-nosed steel with dynamite entrails
for a dozen miles, yet they are confronted with twelve-
inch armour of backed and hardened steel, water-
tight compartments, and targets moving thirty miles
an hour. Each advance in attack has brought
forth, as if by magic, a corresponding advance in
defence.
With life it has been the same : if one species
happens to vary in the direction of greater in-
dependence, the inter-related equilibrium is upset,
and cannot be restored until a number of competing
species have either given way to the increased
pressure and become extinct, or else have answered
8—2
116 ANIMAL INDIVIDUALITY [CH. v
pressure with pressure, and kept the first species in
its place by themselves too discovering means of
adding to their independence. While the balance
of power lasts, variation no doubt takes place, but
there is no strong necessity to guide it. Once let
a large, favourable variation take place in a species,
however, so giving it a handicap, and then for its
competitors natural selection is at once made more
active — they must perish or else adjust themselves
by a variation, generally in a similar direction. So
it comes to pass that the continuous change which
is passing through the organic world appears as
a succession of phases of equilibrium, each one on
a higher average plane of independence than the one
before, and each inevitably calling up and giving
place to one still higher.
This digression was necessary to give some ex-
planation of the succession of ever more perfect
individualities, and the continual repetition of the
same methods in their attainment.
Space forbids more than the merest outline of the
developments of individuality after it has attained
its second grade. We have seen (p. 64) that the
method of aggregate differentiation is now for a time
the less important : it still, however, exhibits some
interesting points.
To start with, division of labour in colonies of
second-grade individuals, as in colonies of cells,
Fig. 10. Part of a colony of Hydractinia. dz, dactylozooid (defensive
person) ; gz, gastrozooid (nutritive person) ; &, blastostyle
(asexual reproductive person); gon, gonophores (sexual repro-
ductive persons) ; rh, hydrorhiza (creeping stolon). (Magnified.)
(After Allman.)
118 ANIMAL INDIVIDUALITY [CH.
almost universally sets in first between the nutritive
and the reproductive functions — the somatic and the
germinal.
The Hydroids and their relations give us a series
closely parallel at first, though in a different grade
of individuality, with that of the Volvocidae, but
exceeding it considerably in length. Hydra, one of
the simplest hydroids known (Fig. 3, p. 39), has, like all
others, the power of budding ; but its buds eventually
become detached, so that it never forms more than
a very small and temporary colony. Besides this,
there is no division of labour among different polyps ;
all are alike, and whether they shall reproduce
sexually or asexually is dictated to them by the
external conditions.
Then come the colonial forms : and all of these
show some division of labour. All, for instance, when
ripe, bud off special sexually-reproductive individuals
in the shape of little jelly-fish or medusae. Some-
times any polyp of the colony may be able to give
birth to one of these, but very often the ordinary
polyps reserve themselves for feeding, and special
mouthless polyps exist for the one purpose of budding
off the jelly-fish ; they are the producers of the
reproducers of the colony. It seems to be only later
that the somatic functions, the functions pertaining
to the single colony as opposed to the race, get
differentiated, as in Hydractinia (Fig. 10), where there
v] LATER PROGRESS 119
are special polyps that defend the colony as well as
those that nourish it1.
All these species are sedentary for most of their
lives ; history again repeats itself, for once more it
is in the free-swimming forms that the members of
the colony have been most modified, most subordinated
to a higher individuality.
The Siphonophora, close relations of the hydroids,
are a group of beautiful pelagic creatures, which
slowly drive their trailing length through" the water
by an array of pulsating bells. Besides these loco-
motor organs, there are in the colony organs for
feeding, for reproduction, for defence, for offence,
and for flotation (see Fig. 11). Most of these
apparent organs are really modified individuals,
either of the polyp or medusa type. The reproductive
"organs" are sometimes detached as perfect jelly-
fish ; the swimming-bells and the protective bracts
often show unmistakeable vestiges of medusoid
structures. The nutritive "organs" are very like
an ordinary polyp, but without tentacles, and the
1 It is interesting to note that in the Polyzoa, another group of
colonial animals, there has been a different kind of division of labour.
The ordinary animals both feed and reproduce the colony, and defence
is undertaken by much modified persons called Avicularia (from their
resemblance to birds' heads with snapping beaks). Here the
differentiation is between most of the somatic and all the germinal
functions on one side, and a single somatic function on the other. In
some forms there are no Avicularia, the colonies then consisting of
only one kind of person.
120 ANIMAL INDIVIDUALITY [OH. v
defensive organs usually have a structure like that of
the defensive polyps in a hydroid like Hydractinia.
There can be no doubt therefore that the various
" organs " do really represent modified hydroids ; and
as these are themselves individuals of the second
grade, a Siphonophoran is therefore an individual of
the third grade. The same process — the subordina-
tion of the lower individualities to a higher — which
we traced from a simple flagellate up to Volvox is
traceable again from Hydra to the Siphonophora : but
the interesting point is that nowhere else in the animal
kingdom is there an unbroken series — a series in
which we can affirm positively that beginning and end
are close relations — of such length. In the majority
of Siphonophora, the persons of the colony have
mostly only a historical individuality : some of them
are sometimes so much modified and reduced that it
has baffled all the zoologists to decide whether
they are homologous with individuals or with mere
appendages of individuals : and in function each is
devoted so little to itself, so wholly to serving some
particular need of the whole, that if one were
separated from the rest, it would appear a perfectly
useless and meaningless body to an investigator who
did not know the whole to which it belonged. There
are zoologists who say it is incredible that the cells
of the Metazoa can be homologous with independent
beings like the Protozoa, impossible that a colony
Fig. 11. A, Diphyes campanulata (natural size). B, a group of
appendages (cormidium) of the same Diphyes (magnified). (After
C. Gegenbaur.) a, axis of the colony; wi, nectocalyx (swimming
'organ'); c, sub-umbral cavity of nectocalyx; v, radial canals
of nectocalyx; o, orifice of nectocalyx; t, bract (protective
'organ'); n, siphon (nutritive 'organ'); d, gonophore (re-
productive 'organ'); i, tentacle (defensive 'organ').
122 ANIMAL INDIVIDUALITY [OH.
should ever give rise to a single individual of a higher
order than its members (see 5, p. 304). To them we
commend the example of the Siphonophora, and pass
on to consider some other individualities, formed
through aggregate differentiation, but after an en-
tirely new fashion.
To start with, we have the old but ever interesting
fact of symbiosis, where two organisms as it were
inter-penetrate, entering into a very close relationship
from which both parties derive profit. The classical
examples of symbiosis are the Lichens, which, long
supposed to constitute a distinct group of plants,
were in the middle of last century discovered to be
actually a mixture of two organisms, one a colour-
less fungus, and the other a green plant — a simple
alga. For the details of their organization any text-
book of botany can be consulted : here it must
suffice to say that there is a perfectly definite arrange-
ment of the algal and fungal constituents. The in-
teresting thing about them is that they will grow, as
anyone can see for himself, in situations which no
other plant would tolerate, so that both plants must
obviously derive advantage from the combination.
Put very briefly, the facts are these : fungi can only
get the carbon of their food from organic matter,
while green plants have the power of using the
energy of light to appropriate carbon from the
carbon dioxide of the atmosphere. In respect of
v] LATER PROGRESS 123
the absorption of water and mineral salts, however,
the fungus seems to be the better equipped. Thus
(division of labour once more) the alga supplies
Fig. 12. Physcia parietina ; building up of the Lichen out of the
Alga and the Fungus. A, a germinating fungus-spore (sp) which
has seized upon two cells («, a) of the alga Cystococcus humicola.
5, more advanced stage. The spores of the fungus have formed
a network in which are embedded numerous algal cells ( x 400). .
(From Scott, after Bonnier.)
carbon compounds for both, the fungus looks after
most of the rest of the nutrition, and also shelters the
alga from frost and drought.
Algae identical with the green cells of the lichen
124 ANIMAL INDIVIDUALITY [CH.
are found free-living in spots less exposed than those
where lichens grow: the alga, that is to say, can
exist separately, but in the partnership grows more
luxuriantly and has a wider range. The fungus, on
the other hand, though it has been grown separately
in an artificial medium, cannot develop in nature
unless it meets with some algal cells. Fig. 12 shows
a young fungus which has just germinated among a
group of algae and is now sending forth little tentacles
to seize and enwrap them.
The fungus gains more than the alga, but this
does not prevent the combination of both, the lichen,
from being a very definite individual. A lichen on
a barren rock is a something whose continuance
as such and in such a situation is dependent upon
the co-operation of its two constituents. Here the
division of labour is given beforehand in the two
kinds of plants, and the new individuality simply
arises from the fitting together of these two separate
beings into a very close and special relation.
This relation is, however, only a special case of
the general relation existing in nature between green
plants and all other organisms. Put very crudely,
the relation is this : — green plants can build up
protoplasm from water, carbon dioxide, and mineral
salts : the protoplasm thus formed is the ultimate
source of all nourishment to the rest of life. Animals
either eat green plants or else eat other animals
v] LATER PROGRESS 125
that eat green plants ; many bacteria feed on the
dead tissues of animals and plants, bringing about as
a result of their activity the phenomenon known as
decay ; and fungi live to a great extent on the
substances produced during decay. Meanwhile, how-
ever, the waste products of the current of metabolism
and the final products of decay, which come eventu-
ally to be degraded to simple stable substances such
as water, carbon dioxide, ammonia, and nitrates, get
diffused in the soil, and form the basis once more of
the green plant's activity.
In a sense, therefore, the whole organic world
constitutes a single great individual, vague and badly
co-ordinated it is true, but none the less a continuing
whole with inter-dependent parts : if some accident
were to remove all the green plants, or all the bacteria,
the rest of life would be unable to exist. This in-
dividuality, however, is an extremely imperfect one —
the internal harmony and the subordination of the
parts to the whole is almost infinitely less than in the
body of a metazoan, and is thus very wasteful ; instead
of one part distributing its surplus among the other
parts and living peaceably itself on what is left, the
transference of food from one unit to another is
usually attended with the total or partial destruction
of one of the units.
Within this biggest system, nature has been per-
sistent in her efforts to create other "naturally-isolated
126 ANIMAL INDIVIDUALITY [OH.
systems," other individualities. Out of every little
accidental company she tends to make an inter-related
whole whose parts are largely dependent on each other,
and only slightly on other wholes or their parts.
It will be necessary to give a few more examples
of the inter-relation of two distinct species before
developing this idea. A very instructive example is
that of Convoluta roscoffensis, a marine flatworm.
Its story has been so clearly told by Prof. Keeble (10)
that here an outline will be enough. In nature, the
worm is always associated with a unicellular green
plant which lives in great numbers beneath its skin.
The plant on the other hand is found abundantly
apart from the worm, but swarms round the egg-
capsules in order to procure nitrogenous food, and
gets ingested by the young animal. Unless this
happens, the worm cannot develop further — the
presence of the green cells is the only stimulus which
will start its machinery on the next stage of its
working. At first both members gain from the
association, much as in the lichen, but finally, after
the worm (which at last takes no food, but depends
entirely on the surplusage of the alga) has produced
its eggs, it finds itself short of nitrogenous material,
and begins attacking and digesting the green cells ;
they cannot last for ever, and when they are all gone
last of all the worm dies also, trusting to chance that
its young will find new algae. This shows a transition
v] LATER PROGRESS 127
from symbiosis to parasitism, though the host here
enters the relation of its own free will. Convoluta
somewhat resembles an employer of slave-labour in a
country where slaves are very kindly treated : the
green slaves are well provided for during their in-
dividual lives, but they have sacrificed the power of
further perpetuating their species. A growing Con-
voluta plus its contained green cells is therefore that
anomaly, a temporary individual.
Take next a case of true parasitism. With most
internal parasites, such as trypanosomes (the flagel-
lates which cause sleeping-sickness and other diseases),
or tapeworms, each species of parasite is confined
normally to one host-species, and cannot come to
perfection elsewhere. It is often extraordinarily
closely adapted to its environment both in structure
and life-history, as a study of any tapeworm will
show ; but that environment is an extremely limited
one.
After this consider an apparently very remote
subject — the relation between insects and flowers.
I need here merely point out that many insects, such as
bees and butterflies, procure all their food from the
honey or pollen of flowers, and that most plants with
conspicuous flowers rely exclusively or chiefly on in-
sects for their fertilization, and so for their continuance
as species. Both insect and flower have been radically
modified in structure and appearance through this
128 ANIMAL INDIVIDUALITY [CH.
mutual relation. Most flowers are fairly catholic in
their tastes, and are adapted for fertilization by a
number of different insects, and the same is true,
mutatis mutandis, of the insects. But sometimes
the relation is a much narrower one, till finally an
insect may be able to get food only from one particular
flower, the flower to be fertilized only by this parti-
cular insect. A relation of this degree of intimacy
(though with not quite the same purposes) is found
between the Yucca-plant and a moth of the genus
Pronuba (Fig. 13). Here (for the details I must again
refer the reader to other books ; e.g. (17), Vol. i, p. 201)
the Yucca can in nature only be fertilized by the one
agency of the moth : she, when the time comes for
egg-laying, flies to the Yucca, rakes up a large ball of
pollen by means of a unique structure on her head,
and then flies with the ball to another flower ; there
she sticks her long and curiously-shaped ovipositor
into the ovary of the flower, and lays her egg among
the unfertilized seeds inside. Last she lifts the pollen-
ball on to a special hollow on the top of the stigma,
and pokes it firmly down. The pollen fertilizes the
ovules, of which there are about two hundred, and
they start developing into seeds ; meanwhile the cater-
pillar hatches, and feeds at the expense of the seeds.
However, it only needs some twenty or so before
undergoing its transformations into pupa and moth,
and leaves the rest to grow into new Yucca-plants.
v]
LATER PROGRESS
129
The whole proceeding is of great interest, showing
as it does the blind and instinctive nature of the
Fig. 13. The Yucca and its Moth (Pronuba yuccasella). A, ovipositor
of the moth, op, its sheath; sp, its apex; op', the protruded
oviduct. B, two ovaries of the Yucca, showing the holes by which
the young moths escape, and (r) a caterpillar in the interior. C,
head of the female moth, with the sickled-shaped process (si) on
the maxillary palps for sweeping off the pollen and rolling it into
a ball, mx', the proboscis ; au, eye ; p't base of first leg. D, longi-
tudinal section through an ovary of the Yucca, soon after the
laying of two eggs (ei). stk, the canal made by the ovipositor.
organisms' actions, and giving us an example of two
species absolutely dependent on each other for their
H. 9
130 ANIMAL INDIVIDUALITY [OH.
continued existence. If the moth had not the struc-
ture to form the pollen-ball and the instinct to put it
on the stigma, the ovules would not be fertilized and
her offspring would have no food; and if the plant
was not prepared to sacrifice some 10 per cent, of its
brood, the rest would never develop at all. Here it
is of course the two species that are affected, while
the single moth and the single plant do not depend
on each other in any way ; but the essential point of
the relation — the mutual helpfulness of two unrelated
kinds of protoplasm — remains the same.
Now return and consider these various relation-
ships from the point of view of individuality. The
different species of living things and their members
are all bound up, though but loosely, into a general
whole. Any single species relies on others for some
of the necessities of its existence. In many green
plants this dependence on other species is very slight
and very indirect, while animals, owing to their mode
of nutrition, are always directly dependent on the one
or many organisms on which they feed. None the
less, in nett total of true independence most animals
are far ahead of plants. They have had to make more
effort to get their food, and throughout life, effort
always seems to bring in its train advantages, unfore-
seen and unconnected with the effort's immediate
object. To give an extreme example, the eyes and
ears and other sense-organs of animals were developed
v] LATER PROGRESS 131
chiefly for the capture of prey and the avoidance of
enemies; but once formed, they were the starting-
point for the life of consciousness that has culminated
in ourselves. A blind deaf-mute child can be fed and
live a healthy physical life ; its mind, however, scarcely
exists :
"for the book of knowledge fair
Presented with a Universal blank."
But wisdom at one entrance still can find a way —
through the gateway of touch ; and the story of Helen
Keller, the American girl who became blind and deaf
and dumb in infancy, will show how absolutely de-
pendent on external stimulus, even in its dealings
with the abstract and the non-spatial, is the mind of
man.
The necessity for effort — the "struggle for exist-
ence" in the most general sense — has from age to age
raised the average level of independence, the measure
of individuality s perfection in living beings. In spite
of this general rise of level, there has been in every
age a falling away, a decline in perfection of in-
dividuality in certain species. This decreased in-
dependence reveals itself not only as structural
degeneration, but also in degeneration's opposite,
structural specialization. There is, however, a
common cause beneath these opposed effects, and
that is over-close adaptation, adaptation to very
narrow conditions.
9—2
132 ANIMAL INDIVIDUALITY [OH.
It is self-evident that all organisms must be more
or less adapted to their surroundings ; in other words
they must be more or less dependent upon their
environment. Failure to exist in any but a very
limited environment is obviously a weakness, a lack
of independence, and it seems to be a fact that
adaptation to any such limited environment makes
it impossible or very difficult for an animal to exist
in any other environment. The very success of the
adaptation decreases the creature's adaptability.
The adaptation may be concerned only with in-
organic nature, as when plants are adapted to
conditions of temperature, light and moisture, or
only with other animals or plants, or with both. Let
us take the second as being most germane to our
present purpose. The nutrition of animals falls
within this province, since they are always dependent
on the protoplasm of other living species for their
food. This is a limitation, but its boundary is a wide
one. The animal may either make an effort1 to
secure its food, or it may prey parasitically on the
labours of another animal. Both ways, if too special
adaptation is allowed, may lead to a back-sliding in
individuality. We can take a series of examples
. l A metaphorical effort, as when a carnivorous species acquires
new powers of speed to run down its prey, or an actual effort, as
when the members of that species make use of those powers.
v] LATER PROGRESS 133
from birds. The Rook and the Sparrow are almost
omnivorous, and therefore very independent as regards
food-supply. A bird like the Swallow is a little more
dependent. In its large gape and strong flight it
shows a general adaptation for catching small insects
on the wing, but as long as they are insects and
small and flying, it is content ; it has taken advantage
of a common property of many insects, and is de-
pendent in no narrow way. Dependent it is, however,
and when the insects fail it must migrate.
Finally, such a bird as the Skimmer (Rhynchops
nigra) exhibits a very special adaptation indeed.
Darwin (3, p. 137) gives a graphic account of them.
" The beak is flattened laterally.. . .It is flat and elastic
as an ivory paper-cutter, and the lower mandible,
differently from every other bird, is an inch and a
half longer than the upper/' When feeding, "they
kept their bills wide open, and the lower mandible
half buried in the water. Thus skimming the surface
. . .they dexterously manage with their projecting lower
mandible to plough up small fish, which are secured
by the upper and shorter half of their scissor-like
bills." This strange bill is without doubt an ex-
tremely efficient instrument for catching fish near
the surface of the water, but the length of the lower
mandible, the very particularity which makes it so
efficient for this one purpose, renders it unavailable
for any other. The narrow domain where air and
134 ANIMAL INDIVIDUALITY [OH;
water meet it has made its own, but to that one
domain it is rigidly confined.
The path to parasitism, in spite of apparent
differences, is very similar. Here too what the
animal seeks is adaptation to an environment which
by very reason of its peculiarity and narrowness is
not already occupied by other competitors. Eventu-
ally the fate of the parasite becomes bound up with
that of the host. The final result is thus the same ;
the form which has made the too-special adaptation
loses independence.
Such happenings the phrase-monger will find
place for under some vague, comprehensive title such
as " Filling a vacant place in the Economy of Nature,"
and be content. But, though it is undoubted that
the pressure of the struggle is always forcing life
into these vacuums of vacant spaces, we have to look
further before we find what the effect on life will be.
Then we see that the process is not always so wholly
satisfactory as phrase would make it. In our par-
ticular cases the result of " filling a vacant space " is
that one species gets preyed upon, and the other, the
claim-staker, though gaining the gold in the vacant
claim, thereby ties himself down to that little plot of
ground, and sinks in the scale of individuality.
Now suppose that the one organism does not
merely rush into a ready-made vacuum provided by
the other, but that the two should conspire together
v] LATER PROGRESS 135
to create a vacuum of their own, into which, as fast as
it is created, they jointly creep. This is in effect what
happens when two species become mutually depen-
dent. Here again the relation is at first a general
one, as between insects and flowers, but at the last
may get very special, as between the Yucca and its
moth. Both species here have lost independence. The
Yucca, for instance, has to be propagated artificially
in Europe, for when it was brought over the moth
was left behind, and so no seed can be set. At first
sight, then, such a system appears like a double
parasitism, and twice the evil that parasitism brings
should be its portion. This is not really so, for while
the true parasite takes what he can get and gives
nothing in return, here each pays the other willingly,
for services rendered. In extremes of parasitism
there is maximum waste; mutual aid (though it
implies mutual dependence) establishes minimum
waste. Moth and Yucca together constitute a system
which is harmonious and economical because division
of labour is at work : each does what it can do best
and gives of its superfluity to its partner. If the
two parts have sunk in the scale, yet by that very
sinking the beginnings of a new whole have sprung
up. They have lost in independence, but something
else — the system formed by their combination-
has gained in harmony. Put in other words, their
own individuality has become impaired, but this is
136 ANIMAL INDIVIDUALITY [CH.
compensated for by the formation of a totally new
individuality, rudimentary though it be. If the parts
of the system, instead of being related by but one
tie and for a short space only, were to be brought
into relation for the whole of their lives, the resulting
system would have the chance of becoming not only
more harmonious, but even a more independent
individuality than was either of its parts before their
mutual adaptation — a consummation actually realized
in the Lichens.
This necessity for the parts of a compound in-
dividual to lose their own independence for the
ultimate greater independence of the whole — this
increasing mutual parasitism of the units within an
individual — is in fact a brief statement of the main
facts observable concerning internal differentiation.
Internal differentiation, indeed, to be strictly accurate,
is the only way in which individuals are formed, for
aggregate differentiation is only a convenient label
for the combination of two processes — first the forming
of an aggregate, be it of molecules, cells, or persons,
and then the welding of this mere aggregate into a
true individual by means of internal differentiation.
The progress of the individual of the second grade
is in essence a progress towards greater complexity,
more harmonious co-ordination, higher independence ;
this is revealed to the eye in the multiplication and
specialization of its various kinds of cells. When it
v] LATER PROGRESS 137
is reflected that these lesser individuals were originally
all alike and all self-supporting, the modifications
which they have undergone are nothing short of
amazing, as a glance at any text-book of histology
will show. We can but mention a few of the most re-
markable. For shape, the ordinary nerve-cell (Fig. 14)
is striking enough ; the cell-body is an ordinary, some-
what polyhedral mass of protoplasm, but from it are
given off branching processes which divide and
sub-divide and with their finest sub-divisions come
into contact with the branches of other nerve-cells ;
and at one point runs out a single thread, the nerve-
fibre, which, though its thickness is to be measured
in hundredths of an inch, may yet reach a length of
several feet before it finds the muscle it is to move
or the sense-organ whose message it is to carry.
Remarkable in another way are the epithelial cells
of our skin, which, continually produced in the deeper
layers, undergo a gradual metamorphosis into the
thin plates of horny matter called scurf, or scarf-skin ;
by their perpetual wearing off and replacement from
below, they give us an outer covering which shall be
at once pliant and sensitive, of considerable strength,
and quick-healing.
When an individual's only duty is to commit
suicide for the good of the society to which he
belongs, the process of subordination has gone
a very long way. In what are known as syncytial
138 ANIMAL INDIVIDUALITY [CH.
tissues it has gone perhaps still further : here the
cells, surrendering all separateness of existence, have
fused to form mere sheets of continuous protoplasm
studded with nuclei. These syncytia are only the
final outcome of a process whose beginnings we saw
in Volvox and Haplozoon — the connection of the
separate cells by means of strands of protoplasm
passing from one to another. These connections
seem to exist in all multicellular green plants, and
have now been demonstrated in a great number of
animals1. Many zoologists indeed believe that the
fine endings of the nerve-fibrils are always in direct
protoplasmic continuity with the organ they supply.
It is worth remembering that the actual history
of every individual runs roughly parallel with what
we know of the history of the race. Those who
cannot bring themselves to believe that the ancestor
of a nerve-cell, for instance, was once independent
and capable of all the functions of separate existence,
often do not consider that every nerve-cell started its
life simple, rounded, and undifferentiated, only later
throwing out its complex branching processes, and
later yet coming into protoplasmic continuity with
other cells, originally far distant in the body (Fig. 14).
In many animals indeed every individual epi-
tomizes in its own the history of the race. Starting
as a fertilized ovum, an individual of the first grade,
1 See Dobell (5) for facts and references.
v]
LATER PROGRESS
139
it next becomes a " colony " of nearly similar cells,
and then an obvious second-grade individual, with
(e)
(c) (b) (a)
Fig. 14. Five stages in the early development of a nerve-cell from
the brain. In (a) the rudiment of the nerve-fibre is seen. In
(c) the dendrite with its branching processes has become obvious.
(e) does not represent the final stage ; in the adult nerve-cell
size and complication are many times greater. (Highly magnified.)
(After Kamon Cajal.)
outer protective and inner nutritive layer. Then
140 ANIMAL INDIVIDUALITY [OH.
comes the internal differentiation of this individual :
blood-cells and blood-vessels, nerve-cells and sense-
organs, muscles, sinews, bone, kidney, liver — kind
after kind of cell is created. And let it never be
forgotten that in the embryonic development of any
and every individual all these and many others are
descendants of a single and a simple cell.
It is noteworthy that the course of internal
differentiation has over and over again — in worms,
in insects, in Crustacea, in spiders, in molluscs, and in
vertebrates — tended in the same direction — towards
the formation of a Brain. Brain-development has
usually gone hand in hand with the specialization of
other organ-systems — the brain seems a mere bit
of machinery necessitated by the complexity of the
other parts. In the higher insects and the higher
mammals, however, the brain seems to have tran-
scended all the other parts of the body, to have gone
farther than they in specialization, and to be now
in truth the master by whom the rest are to be
employed.
This development of sense-organs and brain has
had great influence on the progress of individuality.
We do not usually stop to consider in what dense
darkness the majority of living things must live and
move and have their being. Without brain or sense-
organs, theirs must be a dim and windowless existence.
The world lies waiting round about ; but it cannot
v] LATER PROGRESS 141
make its way into their beings. Or say, the world
is locked, and living things must make their own
keys to it. So it is with men : educating their minds,
they forge key after key, each opening a new chamber,
letting in a new flood of light from every material ob-
ject. Show a flower to an aboriginal savage : what he
sees is something very different from what Wordsworth
or Sir Joseph Hooker would have seen. What he
sees, however, contains more of reality than what
a beetle or a snail, with their imperfect eyes, could
see. The effect produced on an organism when some
object is presented to its senses thus depends partly
on the perfection of its sense-organs, partly on that
of its brain. As we go down the scale, both dwindle :
veil upon veil is let down : till at the last there is an
almost utter darkness, and not of sight alone.
It is this darkness at the base of the animal king-
dom which has there made it almost imperative that
the parts of an individual should cohere physically ;
separate them and they would be lost, and could
never enter again into their mutual relationship.
Once produce a sense-organ, however, which with the
brain behind it is capable of clearly perceiving and
accurately localizing distant objects, and it at once
becomes possible to construct an individual, such as
an ant-community, whose parts, though not contiguous
in space, are yet bound together as fast as the cells
of a sponge or the persons of a Siphonophoran ; here
142 ANIMAL INDIVIDUALITY [OH.
as elsewhere the real bond is an impalpable one —
mutual dependence.
The communities of ants and bees are undoubted
individuals. Wheeler in a recent paper (18) has
abundantly justified this view from a somewhat
different standpoint. Here I can only say that if
the ideas and definitions put forward in Chap. I are
accepted, their individuality is beyond dispute. In
spite of space, I cannot refrain from giving one
example of the lengths to which internal differ-
entiation of parts can go in such apparently loose-
connected wholes. In several species of ants there
are special workers whose duty it is to imbibe honey
till their fair round bellies are drum-tight, then to
suspend themselves, a row of living jars, from the
roof, and there to wait until their store is needed by
the colony and they are taken down arid tapped for
general consumption.
One interesting property gained by brains and
sense-organs :— organisms possessing them can easily
enter into more than one individuality. The Yucca
and its moth, for instance, constitute a definite
individual that works for its own perpetuation. But
their time of contact is a short one ; and there is
nothing to prevent the moth from entering into re-
lations with some other flower for the sake of food (in
return of course fertilizing the flower) and so forming
together with it another " whole with inter-dependent
v] LATER PROGRESS 143
parts working for its own continuance" — another
individual.
When we come to man, this power possessed by
one unit of entering into more than one individual
"at once" (see note, p. 13) becomes very marked.
A man can very well be at one time a member of
a family, a race, a club, a nation, a literary society,
a church, and an empire. "Yes, but surely these
are not individuals," — I seem to hear my readers'
universal murmur. That is a question which neither
the size nor the scope of this book permits. Here
we can but express a pious opinion : — that they are
individuals, that here once more the tendency towards
the formation of closed systems has manifested itself,
though again in very varying degrees, so that some
of the systems show but a glimmer of individuality,
others begin to let it shine more strongly through.
That their individuality is no mere phantasm I think
we must own when we find men like Dicey and
Maitland (12, p. 304) admitting that the cold eye of
the law, for centuries resolutely turned away, is at
last being forced to see and to recognize the real
existence, as single beings that are neither aggregates
nor trusts, of Corporate Personalities.
This being so, it yet remains true that the state
or society at large is still a very low type of individual :
the wastage and friction of its working are only too
prominently before our eyes. With the examples of
144 ANIMAL INDIVIDUALITY [OH.
what life has accomplished in producing our own
bodies, we can never despair. But we must not be
too far tempted by biological analogies : the main
problem is the same, but the details all are new.
The individuals to be fused into a higher whole are
separate organisms with conscious, reasoning minds
— personalities ; and the solution will never be found
in the almost total subordination of the parts to the
whole, as of the cells in our own bodies or the sweated
labourer in our present societies, but in a harmony
and a prevention of waste, which will both heighten
the individuality of the whole and give the fullest
scope to the personalities of all its members.
CHAPTER VI
THE RELATION OF INDIVIDUALITY TO MATTER;
CONCLUSION
"Shall man into the mystery of breath,
From his quick-beating pulse a pathway spy?
Or learn the secret of the shrouded death,
By lifting up the lid of a white eye ? "
MEREDITH.
A VERY striking experiment can be made on many
of those free-living flatworms, the Planaria. If they
are cut in two longitudinally, the halves will regenerate
into perfect wholes, and this whether they are fed or
VI]
RELATION TO MATTER
145
not. If not fed they present us with a strange
spectacle (Fig. 15). Without food, they cannot of
Fig. 15. Planaria lugubris. Four stages in the regeneration of a
whole from a longitudinal half. The dotted line in (a) marks
the line of the cut. The stippled areas represent regenerated
tissue. The figures are all drawn to scale. (After Morgan.)
(Slightly magnified.)
course rebuild their missing block of buildings as we
should, with new bricks : indeed, as energy has to be
H. 10
146 ANIMAL INDIVIDUALITY [OH.
expended in the construction, some of the existing
materials must be sacrificed as energy-producers, so
that by the time the bit of worm-protoplasm has turned
itself into a worm, it has actually decreased in bulk
(Fig. 15). The half- worm has never ceased to exist as
a half, but has somehow managed to become an ever
smaller half while remodelling itself continually and
at the same time handing over material for the
building of what is missing. Finally the other half
is completed — a whole worm has been made ; up till
now the old half had been decreasing rapidly in size,
the new increasing almost as fast. From the time
that a whole is formed, both halves behave alike,
decreasing slowly together as a result of starvation.
This and many other similar facts tend to show
that the relation of form, and so (since specific form
or structure is only the visible machinery of a specific
working) of individuality in living things to its
physical basis of matter, is primitively a simple one,
though one that is at variance with all our precon-
ceived ideas. It seems to be this : any separate mass
of one kind of protoplasm will be able to, or rather
must, make itself into an individual with the form
characteristic of the species. The only provisions are
that it is neither too large nor too small within certain
defined limits and, of course, that the external con-
ditions are favourable.
Facts suggesting this we have seen in Clavellina,
vi] RELATION TO MATTER 147
in Stentor, and in Sycon1 : indeed, as I have said, it
really seems to be an original attribute of life, only
more wonderful and startling than ordinary embryonic
development because it is no regular part of the cycle
of the species. Through its help the animal can extri-
cate itself from positions in which it has never before
been.
But, like most other primitive attributes of life, it
has undergone considerable restrictions in the course
of evolution. Animals, like men, cannot have their
cakes and eat them. Three main factors have led
to a restriction of this power of regeneration. The
first is the formation of different substances for the
performances of different functions, and their subse-
quent segregation into different regions of the body.
These substances may get so specialized, so different
from each other and from their common ancestor,
that one cannot produce the other, and the presence
of both is necessary in a mass of substance which is
to give rise to a whole individual. In Stentor, for
instance, although both nucleus and cytoplasm alike
are living Stentor-protoplasm, yet a bit of one with-
out the other will not regenerate. Here the two
substances have been segregated by internal differ-
entiation within the cell. Something similar occurs
in Sycon, where the collar-cells by themselves cannot
regenerate the other forms of tissue necessary to make
1 pp. 46, 47 and 94 respectively.
10—2
148 ANIMAL INDIVIDUALITY [CH.
a complete sponge ; here aggregate differentiation has
been at work, and whole cells and tissues are affected
instead of parts of cells.
The second narrowing factor is harder to precise ;
but though we do not know its exact nature, we can
often see it at work. There are many animals, such
as man himself, where regeneration is almost non-
existent although in any given case all the necessary
substances and kinds of tissue would appear to be
present. Here the failure to regenerate seems to
stand in some general relation with the degree of
specialization of the tissues; most animals can
regenerate more completely when young or embryonic
than when they are grown up.
The third factor is more obvious : certain bits of
organic machinery are of such a nature that it is
physically impossible for the animal to live at all if
they are seriously tampered with. It is just because
our blood-circulation is so swift and efficient and our
nervous system so splendidly centralized that damage
to heart or brain means almost instant death to us,
while a brainless frog will live for long, and a heart-
less part of a worm not only live but regenerate.
Thus here again sacrifice is at the root of progress,
and only by surrendering its powers of regeneration
and reconstitution has life been able to achieve high
individualities with the materials allotted her.
But this original property of living matter is
vi] RELATION TO MATTER 149
important to us in one way. We begin to realize
what an influence the correlation of parts can exert
—how one part can affect others by its mere presence
or absence. In Stentor, each bit that if separated
from the rest would grow into a perfect little whole,
remains as a part as long as it is connected with the
other parts. If it forms a part, it is because of its
relation with other parts ; if it forms a whole, it is
because it is freed from that relation. Whatever it
does, in fact, is due to the tendency of any separate
mass of Stentor-protoplasm to form a whole Stentor.
Exactly similar is the behaviour of the blastomeres
or separate cells of the segmenting egg (p. 69) only
here the subordination is in one way more startling,
for each of them is a single cell and represents
historically a whole individual. Similarly in all
animals where small fragments can reconstitute
miniature wholes, the fate of any particular cell in a
fragment is determined very largely by its position
in the fragment, and would be different if the fragment
were of a different size or shape.
This " tendency towards wholeness " thus manifests
itself across cell-boundaries as easily as through the
more continuous substance of a single cell. More
than this, it often seems to disregard them altogether.
Many facts of embryology, as when form appears first
and cells only later, lead us inevitably to a standpoint
resembling that of Whitman (19), when he says of
150 ANIMAL INDIVIDUALITY [OH.
normal development: — "the plastic forces heed no
cell-boundaries, but mould the germ-mass regardless
of the way it is cut up into cells/ ' Such considera-
tions have led him and several others to throw up
the cell-theory altogether, saying that the cells of
a metazoan are not homologous with free-living
protozoan individuals, but are merely convenient
bricks, so to speak, or centres of local government,
produced by the forces of life after the form of the
creature had been established. But such a conclusion
cannot be justified. We must carefully distinguish
between what exists to-day, whether in adult body
or developing embryo of a metazoan, and what we
believe to have happened in the past.
Volvox and Haplozoon, whose cells we can with
no shadow of doubt affirm to be homologous with
free-living Protozoa, show that it is possible for a
higher individual to be evolved from a collection of
lower ones. If we refuse to the Metazoa an ancestor
formed thus by aggregate differentiation, we are
landed in far more and far worse difficulties than
any we escape from. Whitman is right in drawing
attention to the remarkable fact that the so-called
Kupffer's vesicle of embryonic Teleost fish is non-
cellular, a mere thin sheet of protoplasm which is not
even nucleated, whereas it is certainly homologous
with a structure of other vertebrates which is
composed of very definite cells, but to reject the
vi] RELATION TO MATTER 151
cell-theory altogether on this account is not warranted.
Rather should we in such facts see examples of the
extreme lengths to which the degradation of the
individuality of the parts can go — a degradation
which we found to be everywhere (except in man's
societies) a necessary accompaniment of the formation
of a higher individual from an aggregate. Here the
cells have become degraded to the level of mere
bricks, with even less share in determining the form
of the whole than real bricks have in determining
the form of a house. But how different is the
structure of our Sponge or of Volvox — and they
deserve equal consideration with the fish. It is
better to believe in the historical individuality of
the cells and to wonder at the idea of the whole's
form that can thus penetrate the substance and
absorb the individualities of its parts, robbing them
of all their ancestral freedom, as the universal mind
(some would believe) absorbs and loses in itself our
souls at death. But here we have come down to the
bed-rock questions of biology — the old problems of
ordered growth and purposeful working, which are
still shrouded in their dense cloud of ancient mystery.
Yet though, like enquirers who try to push far
after knowledge in any direction, we are at length
brought face to face with the unknown and perhaps
unknowable, we have made some solid progress.
Without discovering the origin or the inner being
152 ANIMAL INDIVIDUALITY [OH.
of individuality, we have been able to see it made
objective in the various streams and masses of proto-
plasm which we call animals and plants, and to trace
an upward progress in its course, at the same time
getting light on many related problems of biology. We
have seen the totality of living things as a continuous
slowly-advancing sheet of protoplasm, out of which
nature has been ceaselessly trying to carve systems
complete and harmonious in themselves, isolable from
all other things, and independent. But she has never
been completely successful: the systems are never
quite cut off, for each must take its origin in one
or more pieces of a previous system ; they are never
completely harmonious, as MetschnikofFs long list
of the " disharmonies " in man will show ; and they
are never completely independent. These very
incompletenesses, due to the limitations of the
material stuff with which life has to work, have
proved the foundations of fresh advance. It is just
because every system is bound to be in some degree
dependent, that a number of systems can adjust their
various ways of dependence to each other, till a
condition of minimum waste and maximum inter-
dependence is gradually set up, and a new system,
better equipped than any and all of the earlier ones,
is made.
These systems are individuals, and it thus comes
about that individuals exist in grade upon grade,
vi] RELATION TO MATTER 153
any one in any grade being able to combine with
others like itself or with others unlike itself to form
the beginnings of a new system, a new individual.
Moreover, within each grade there may exist indi-
viduals of every degree of perfection. At the bottom,
a Gonium-colony is but a possibility of an individual ;
the individual formed by the inter-relation in food-
matters of plants and animals is so vague as scarce
to deserve the name. At the top, Man astounds
by his harmonies, his purposeful completeness, and
power over nature ; but none are perfect. Thus we
must not expect any hard-and-fast rule; there are
many grades, many degrees, and many kinds of
individuality, and each individual must be judged on
its merits, as something really new.
Finally we have learnt to appreciate the historical
point of view, and through it to be brought to admire
the seemingly infinite changeableness of life. On the
one hand we have seen many structures and many
habits of animals that can only be made fully in-
telligible through their history. Each new species
must go through its period of storm and stress while
striving to come into harmony with its environment ;
" And 'mid this tumult Kubla heard from far
Ancestral voices ! "
—the forms and patterns of its forefathers rise up
and will not be denied, forcing themselves into the
154 ANIMAL INDIVIDUALITY [OH. vi
altered mould, and thereby often taking on new and
unfamiliar shapes.
The ancestral plan may persist in spite of present
uselessness, like the elaborate arrangement of the
lines of hair on the body and limbs of man ; or it
may take on some new use, like our Eustachian tube,
in fish-like ancestors a gill-slit. It is by this in-
corporation of the old in the new that we can trace
such adventurous histories as that of the cell-
individual.
But this persistence is not absolute : with necessity
and long lapse of time life seems able to cast away
every vestige of the old forms, as when gills are
replaced by lungs in air-breathing vertebrates, or
when a metazoan structure, once cellular, builds
itself without cells.
All roads lead to Rome: and even animal indi-
viduality throws a ray on human problems. The ideals
of active harmony and mutual aid as the best means to
power and progress ; the hope that springs from life's
power of transforming the old or of casting it from
her in favour of new ; and the spur to effort in the
knowledge that she does nothing lightly or without
long struggle : these cannot but help to support and
direct those men upon whom devolves the task of
moulding and inspiring that unwieldiest individual-
formless and blind to-day, but huge with possibility
— the State.
LITERATURE CITED 155
LITERATURE CITED
(1) BERGSON, H. "Creative Evolution" (Translated). London.
Macmillan. 1911.
(2) CALKINS, G. N. " The Protozoan Life Cycle." Biol. Bulletin
XL 1906, p. 229.
(3) DARWIN, C. " Journal of Researches." London. J. Murray.
1888.
(4) "The Variation of Animals and Plants under
Domestication." London. J. Murray. 1875.
(5) DOBELL, C. C. " The Principles of Protistology." Archiv f.
Protistenkunde xxin. 1911, p. 269.
(6) DOGIEL, V. (Catenata.) Zeitschr. f. Wiss. Zool. LXXXIX.
1908, p. 417 and xciv. 1910, p. 400.
(7) ENRIQUES, P. (Conjugation, &c., in Infusoria.) Arch. f.
Protistenkunde xn. 1908, p. 213.
(8) HUXLEY, T. H. "Collected Scientific Memoirs." London.
Macmillan.
(a) " Upon Animal Individuality." Vol. I. p. 146.
(b) " On the Agamic Reproduction and Morphology of
Aphis." Vol. II. p. 26.
(9) HUXLEY, J. S. (Regeneration in Sycon.) Phil. Trans. Roy.
Soc. (B), vol. ecu. 1911, p. 165.
(10) KEEBLE, F. " Plant-Animals." Camb. Univ. Press. 1911.
(11) LEDANTEC, F. " Theorie nouvelle de la vie." Paris. F. Alcan.
1908.
(12) MAITLAND. Collected Papers. Vol. 3, pp. 285 and 302.
Camb. Univ. Press. 1911.
(13) MORGAN, T. H. " Regeneration." New York. Macmillan.
1901.
156 ANIMAL INDIVIDUALITY
(14) NEWMAN AND PATTERSON. (Armadillo Quadruplets.) Biol.
Bulletin xvn. 1909, p. 181.
(15) PERKIER , E. "Les Colonies Animales." Paris. 1881.
(16) Roux, W. "Der Kampf der Theile im Organismus."
Leipzig. 1881.
(17) WEISMANN, A. "The Evolution Theory" (Translated).
London. Arnold. 1904.
(18) WHEELER, W. M. "The Ant-Colony as an Organism."
Journ. Morphology, 1911, p. 307.
(19) WHITMAN, C. 0. " The Inadequacy of the Cell-Theory."
Biol. Lectures, Wood's Hole, vol. n. 1893, p. 105.
(20) WOODRUFF, L. L. (Life-Cycle of Paramaecium.j Biol.
Bulletin xvu. 1909, p. 287.
APPENDIX A
TABLE TO SHOW THE FIRST THREE GRADES
INDIVIDUALITY; AND TO INDICATE THE
DIFFERENCE BETWEEN ACTUAL AND
HISTORICAL INDIVIDUALITY
OF
(Aj) Individuals of
the First Grade.
(A2) Compound
wholes made up of
first-grade indi-
viduals ; without
division of labour.
(A8) = (B0) Ditto, but
with division of la-
bour (rudimentary
second-grade indi-
viduals).
. (a)
Functioning as wholes:
Actual Individuals.
One of the hypothetical
non-nucleated ancestral
cells (p. 56).
A Protozoan.
A fertilized ovum.
Gonium (p. 102).
Volvox (p. 104).
Haplozoon (p. 107).
Functioning as parts,
but descended from an^
cestors that functioned
as wholes ; thus, though
in point of fact not
actual individuals, they
are morphologically and
historically equivalent
to them, and may be
called Historical In-
dividuals.
A tissue-cell of
or Man.
Hydra
A cell of Volvox or
Haplozoon.
A green cell in Convo-
luta.
158
ANIMAL INDIVIDUALITY
(Bj) Full individuals
of the Second Grade.
(B2) Compound
wholes made up of
second-grade indi-
viduals ; without
division of labour.
(B3) = (C0) Ditto, but
with division of la-
bour (rudimentary
third - grade indi-
viduals).
(Cj) Full individuals
of the Third Grade.
w
Clathrina (p. 90).
Hydra (p. 40).
Man, regarded singly.
Pronuba, in certain re-
spects (p. 128).
Many Sponges.
Many Corals.
Some Polyzoa (p. 119 n.).
Hydroid colonies such
as Bougainvillea (p.
38).
Polyzoa with avicularia
(p. 119 n.).
Siphonophora (p. 119).
An Ant Community (pp.
12, 142).
Human Society (p. 143).
Yucca-plant plus Pro-
nuba (in certain re-
spects) (p. 128).
A Lichen (p. 122).
Convoluta plus its green
cells (p. 126).
W
A single polyp of Bou-
gainvillea (p. 38), or
of a Siphonophoran
(p. 119).
Man, regarded as a Unit
of Society.
Pronuba, in certain re-
respects (p. 135).
Convoluta, considered
apart from its green
cells (p. 126).
A single Ant (p. 142).
APPENDIX B
ON THE DIFFERENCES BETWEEN THE CELLS OF THE
HIGHER PLANTS AND THE HIGHER ANIMALS
It is probable that in certain points the cells of the higher
animals and the higher plants are not strictly homologous with
each other.
Botanists distinguish three main types of elementary structure
among plants, their differences arising out of differences in the
method of cell-division practised (Fig. 16). In the first type
Fig. 16. Diagram to show the three main types of elementary
structure found in plants, (a) coccoid, (b) filamentous, (c)
coenocytic. In each case is shown the sum of the changes
following upon binary division of the nucleus of a single cell.
(Coccoid), the entire cell, with its cell-wall, divides into two
similar and quite separate halves. This is practised, e.g., by
unicellular Algae. In the second type (Filamentous), the cell-
body (cytoplasm and nucleus) divides as before, but the cell-wall
does not divide ; instead, an entirely new party-wall is laid down
between the two cell-bodies, and in this partition small apertures
160 ANIMAL INDIVIDUALITY
are left, through which the two cell-bodies enjoy protoplasmic
communication. This type of organization is found in all the
higher green plants. In the third type (Coenocytic) the nucleus
alone divides, and the final result is a coenocyte — a single over-
grown cell with a single cell-wall and many nuclei. This plan has
been adopted by the Siphoneae (p. 89).
It is obvious that the first method is the most primitive and
will be most generally practised by unicellular organisms; but
whereas it has been abandoned by the higher plants, it seems to
have been retained by the higher animals. Almost the only
difference between the division of a protozoan and a metazoan
cell lies in the fact that the two daughter-cells separate in the
one case, cohere in the other. The essential separateness of the
cohering cells is well seen in the collar-cells of simple Calcareous
Sponges like Clathrina ; here indeed there is even no continuity of
coherence during normal life (p. 93).
Similar if less strikingly separate cells can be seen in many
other groups of multicellular animals, and there can be very little
doubt that the first method of division was employed by the
common ancestor of all M-etazoa1 ; true party- walls like those of
filamentous plants do not exist in animals, and animal syncytia
(tissues formed by the coenocytic method) are undoubtedly
secondary.
We must now try and see what these facts mean. In the
filamentous type the units are still homologous, as units, with the
original units we called cells (p. 56) ; but they have sacrificed a
considerable amount of independence. The whole mode of
division by which they arise is an obvious adaptation to a state
of existence where each is to be part of a continuous whole.
1 It is more than probable that Sponges have an ancestry quite
separate from the rest of the Metazoa : if so, then the common
ancestor of Sponges employed, though quite independently, the same
method as the ancestor of the Metazoa proper.
APPENDIX B 161
In Metazoa the separation of the cells is as a rule total, and
if protoplasmic continuity exists, it appears to be secondarily
produced. As regards their mode of cell-division, therefore, the
Metazoa are more primitive than the Metaphyta; yet in spite
of — or perhaps because of— this very separateness of their units,
there has been a much greater division of labour between
different kinds of units in animals than in plants.
To sum up : the cells of the higher plants and of the higher
animals are both true cells— they are both broadly homologous
with the original units of living matter. But the mode of cell-
division in the two groups, in so far as it concerns the separation of
the cells and the formation of the boundary between them, is not
homologous.
11
INDEX
/= figure. n = note.
Adaptability, importance of, 6
Adaptation, 86 ; to special modes
of life, 77-79, 131 ; not univer-
sal in living things, 57 ; may
be too perfect, 77, 79
Aggregate differentiation, 64, 116
Albatross and wren, 86
Algae, mode of feeding, 122
American water- weed introduced
into England, 71 •
Amoeba, pseudopods of, 1 ; repro-
duction in, 17
Amphibia, regeneration, 46
Animals,food-relation with plants,
125, 130
Ants, 24, 36, 50 ?i, 65, 141, 142,
158
Aphis, asexual reproduction in
summer, 67
Armadillo, produces quadruplets,
68,70
Bacteria, duration of life, 25 ;
lack of sexual process, 71 ; food-
relations, 128 ; lack of formed
nucleus, 59
Bee, and hive, 9; communities of
bees as single individuals, 36,
65, 142
Begonia, regeneration in, 19
Benjamin Franklin's kite, 66
Bergson, . definition of individu-
ality, 1, 9 ; and continuance,
20 n ; indetermination and
brain-machinery, 6
Blastodinium, 110
Blastomere, definition, 69 ; re-
generation of, 149
Bones, brittleness when old, 18
Bougainvillea (Hydroid colony),
37/; 158
Brain, 63, 140; and choice, 6;
and individuality, 29, 65, 83,
141; modifies method of indivi-
duation, 65, 140
Budding, in animals, 38, 79, 80,
118
Bud-sports, 81
Butterfly, metamorphosis in, 75 ;
and flowers, 127
Catenata, 107-114
Caterpillar, metamorphosis, 77 ;
" skin and squash," 78
Caulerpa, a single enlarged cell,
89
Cells, 65, 68, 150; units of
structure in higher animals,
INDEX
163
36 ; form the whole bodies of
protozoa, 38 ; origin of, decreed
by nature of protoplasm, 56, 65;
influence of, upon history of
life, 65 ; size of, 86, 89 ; repro-
duction of, 41 /, 42, 44; modi-
fications of, 137 ; and indivi-
duality, 65 ; independence of,
in some animals, 97; of Sponges,
90-97; of Volvox, 104; of
Catenata, 107
Chess, 14 n
Chick, before hatching, 77
Choano-flagellates, 95
Chromatin, 59
Chromosomes at sexual fusion,
80
Church architecture, 61
Ciliata, sexual process in, 67, 71
Clathrina, 90, 158
Clavellina, regeneration of half
the body, 46, 146
Closed Systems, 9
Coenocyte, definition, 89 n
Colonies, 139 ; how formed, 38 ;
individuality of, 99; of Volvoci-
dae, 102 ; of Hydroids, 36-40,
67, 75, 76; of Siphonophora,
37, 119, 141, 158 ; of corals,
36 ; of Termites, 12 ; of ants,
24, 36, 65, 141, 142 ; of bees,
9, 36, 65; of man, 65, 112, 143
Communities, 24, 36, 65
Comparative anatomy, uncon-
scious, 35
Complexity, importance of, 5
Conjugation, definition, 67
Consciousness, and indetermina-
tion, 6; and continuance, 26;
and personality, 30, 84 ; states
of, 13 ; beginnings of, 29
Continuance, of individuals, 15,
24, 25, 33 ; only partial, 20 ;
increase in, 25
Corporate personalities, 143
Crystals, difference from indivi-
duals, 21, 51, 52
Cytoplasm, 59, 147
Darwin, 1, 6, 133
Death, includes two separate pro-
cesses, 16 ; and growth, 18
Dermal cells, 91-97
De Vries, and mutations, 80
Dicey, on personality, 143
Distomum, 22 /, 23
Division, reproduction by, in
animals, 41 /, 42
Division of labour, 107, 116,
123 ; in man, 112
Dogiel, 107
Double monsters, 68
Echinoderms, 79
Egg, 43, 67-70, 149; a cell, 43
Elephant, 86
Elodea, lack of sexual process
in England, 71
Embryo, of man, 34 ; more than
one formed from a single ovum,
67-70
England, 54
Enriques, and sexual process in
protozoa, 71
Environment, adaptation to,
77-79, 127
Etymology, and individuality, 82,
83
Eustachian tube, 154
Evolution, its meaning, 27 ;
altered point of view due to,
31
Fertilization, 45, 71 ; of ovum
164
ANIMAL INDIVIDUALITY
supposed to mark beginning of
a new individual, 67, 72
Field-mouse and elephant, 86
Fission, in animals, 41/, 42, 71 ;
in protozoa, 67, 71
Flagellum, part of a cell, 90, 102
Flowers, and insects, 127
Fluke of liver-rot, 23
Franklin, B., experiment with
kite, 66
Frog and tadpole, individuality
in, 72, 75-78
Fungi, mode of feeding in, 122
Gamete, definition, 45
Germ-cells, of Sponges, 92 ; of
Volvox, 105
Gonium, 102, 153, 157
Growth, difficulties involved in,
17
Grub, metamorphosis of, 72
Gymnodinium, 109, 113
Hand, relation with rest of body,
9, 10, 15 ; grasping function of,
12
Haplozoon, 107-114, 138, 150,
157
Helen Keller, 131
Heterogeneity, of individuals, 10,
14, 28
History, all-important in Biology,
32, 48 ; as a clue to individu-
ality, 48
Hooker, Sir J., 141
Huxley, J. S., 94
Huxley, Prof. T. H., view of in-
dividuality, 72, 75, 76
Hydra, 39/, 40, 67, 118, 157, 158
Hydractinia, 118, 120
Hydroid polyps, 36-40, 47, 67,
75, 118
Independence of the individual,
3 et seqq., 28, 130, 135 ; per-
fection of, 8, 28; progress of,
87 ; of cells, 97
Individual, 125, 152, 154; certain
organisms naturally regarded
as individuals, 3 ; unconscious
use of word by average man, 3,
35 ; etymology, 3, 82, 83 ;
general definition of, 28 ; de-
finitions by other writers, 67,
83; heterogeneous, 10, 11; in-
dependent, 3 ; unified, 9, 11 ;
continuing, 15, 16, 20, 24, 127 ;
actual, 157; historical, 120,
157 ; degraded to an organ, 120;
man the most perfect, 70 ;
physical continuity of one in-
dividual with its offspring, 46 ;
the perfect, 7, 21
Individuality, 62, 98, 125, 135,
142 ; general definition, 28 ;
tendencies and progress of, 28,
116; etymology of, 3, 82, 83;
various definitions of, 31, 67,
83, 85 ; its attributes, 3, 9, 10,
15, 28 ; compound, 98, 99 ; of
a species, 23-25, 82; spatial,
25; simultaneous, 25; tempor-
ary, 127; historical, 120, 157;
according to Bergson, 1 ; and
man, 31-35, 48, 70, 143 ; and
personality, 30, 34 ; in colonies,
36-40; and regeneration, 46-
47 ; and brain, 6, 29, 65, 83,
140; and sex, 67, 71, 72; and
metamorphosis, 72-80 ; and re-
production, 17, 18; and matter,
18, 29, 30, 146; and hetero-
geneity, 57, 99, 101
Internal differentiation, 60, 136,
140
INDEX
165
Jelly-fish, reproductive in func-
tion in Hydroids, 118, 119 ;
lack of complexity, 6 ; artificial
production of twins and quad-
ruplets in, 69
Jerboa, thigh-muscles, 87
Kangaroo, size of, 87
Keeble, 126
Keller, Helen, 131
Kite, used to bring lightning to
earth, 66
Kubla, 153
Kupffer's vesicle, 150
LeDantec, definition of indivi-
dual, 83
Lichens, compound species, 122,
136, 158
Limbo, 34
Liriope, a jelly-fish, 69
Liver Fluke, 22/, 23, 82
Maitland, 143
Malaria, 5
Man, 148, 153, 157, 158 ; great
independence of, 6 ; and in-
dividuality, 31-35, 70; the
tool-maker, 13 ; communities
of, 65, 112, 143
Materialism, errors of, 85
Medusae, 118, 119
" Merrimac" and " Monitor," first
armoured ships, 115
Metamorphosis, 20 n, 72-80; rea-
son of, 77-80
Metazoa, and protozoa, 43, 44 ;
compound individuals, 36, 44
Metschnikoff, and death, 20 M,
and disharmony, 152
Microscope, 5
Milton, and life before birth, 34
Minoan dancers at bull-fights, 19
Monsters, double, 68
Mutations, and individuality, 80
Nectarine, produced as bud-sport
from peach, 82
Nelson, 115
Nemertine worms, metamorphosis
in, 72-75, 79
Nero, 56
Nerve-cell, 137
Nervous system, 63 ; supposed
basis of individuality, 83
Newt, regeneration of lost organs
by, 46 ; artificial production of
twins in, 69, 70
Nietzsche, 1, 9
Nucleus, 57 n, 59, 89rc, 147; in
sexual process, 71, 80
Organs, and individuals, 120
Ovum, 43, 157 ; erroneously sup-
posed to contain the potentiality
of only one individual, 67 ;
division of, into independent
parts, 67, 139
Paramaecium, reproduction in, 17
Parasites, special environment
of, 113, 127, 134
Particular, in philosophical sense,
9
Peaches, and bud-sports, 82
Peridineae, 109
Personality, definition, 30 ; and
matter, 30; and individuality,
34, 84 ; corporate, 143
Phagocytes, 78
Pilidium, strange metamorphosis
of, 72-75, 79
Planaria, 144
Polyzoa, 119 n, 158
166
ANIMAL INDIVIDUALITY
Pores, of Sponges, 91, 97
Potentiality, 8
Printing press, 16
Printing, and increase of indivi-
duality, 26
Pronuba, 128, 135, 142, 158
Protoplasm, its properties in rela-
tion to individuality, 8, 17, 49,
56 ; its advancing flow, 28
Protozoa, reproduction in, 17, 18,
19 ; free-living cells, 38, 157 ;
and metazoa, 44, 67, 120, 150 ;
views as to individuality of, 67 ;
sexual reproduction in, 67, 71 ;
size of, 88 ; relative lack of
independence, 5
Psychical research, 30
Quadruplets, always given birth
to by one species of Armadillo,
68, 70
Raindrops, influence of electricity
on, 11
Regeneration, 10 n, 11, 19, 21,
46-47, 147 ; an original attri-
bute of life, 46; in Vertebrates,
46 ; in Protozoa, 10 n, 47 ; in
Flatworms,47,144; in Sponges,
94-97
Regulation, 11
Reorganization as opposed to
true regeneration, 95, 145, 149
Reproduction, in Protozoa, 17,
41 /, 42 ; of molecules, 51 ; and
individuality, 18, 19, 40, 42;
by budding, 38, 40; by fission
(division), 41-43; asexual,
38-43, 81 ; sexual, 43-45 ; not
involved in metamorphosis, 77 ;
by cuttings and slips, 80
Rhynchops, 133
Rome, 154
Rook, 133
Roux, extension of idea of natural
selection, 6 ; idea of growth, 17
Salamander, replacement of lost
organs, 46
Scurf, 137
Sea-urchins, artificial production
of twins, quaduplets cfec., 69,
70 ; metamorphosis, 79 n ; will
die if cut in half, 83 n
Self-consciousness, implies exten-
sive individuality, 30
Sense-organs, and individuality,
64, 140
Sexual fusion, 43, 45, 67, 70-72,
80, 81 ; in Bacteria, 71 ; in
Protozoa, 67 ; in Metazoa, 80
Sexual reproduction, 43 ; not es-
sential, 45, 70
Sheep, and Liver Fluke, 23
Siphoneae, single cells, 89
Siphonophora, 119-122, 141, 158
Size, 64 ; advantages of, 5, 7, 86 ;
disadvantages of, 17
Skeleton, 17
Skimmer, 133
Sleeping sickness, 127
Snails, and Liver Fluke, 23, 24
Societies, of man, 65, 143, 158
Solar System, difference from an
individual, 9, 21
Sparrow, 133
Species, 27
Species-individuality, 23-25, 82
Speech, increases individuality,
26, 29
Spermatozoa, 18 n
Spicules, of Sponges, 92, 96
Sponges, 90, 141, 148, 151, 158
Sports, in plants, 80
INDEX
167
Stentor, regeneration in, 10 w, 47,
147, 149
Stomach, in young nemertines, 74,
75
Stylonychia, reproduction in, 41/,
42
Suez Canal, 5
Suicide, 137
Surface-tension, 59 ; effects of,
53, 86 ; alteration of, by living
matter, 55, 86
Surface-volume ratio, 50, 55, 88
Swallow, 133
Sycon, 94 rc, 147
Symbiosis, definition, 122; exam-
ples of, 122, 124
Syncytia, 137
Tadpole, change into frog, 72, 75-
78
Tapeworm, 127
Teeth, in old age, 18
Teleology, errors of, 85
Teleost fish, 150
Termites, 12
Tools, part of man's individuality,
14, 29 ; inorganic organs, 13
Trees, in old age, 18; duration of
life, 26
Trypanosomes, 127
Twins (identical), 68, 70 ; normal
production of, 68, 70; artificial
production of, 69, 70
Volvocidae, evolution of , 102-107,
111
Volvox, 95, 104, 110, 114, 138,
150, 151, 157
Walt Whitman, 114
Warfare, evolution of, 115
Water, its ** metamorphosis," 76
Weismann, on sex, 45
Wheeler, 142
" White ants," 5
Whitman, 149
Woodruff, and lack of sexual
process in Ciliates, 71
Wordsworth, 141
Worms, Nemertine, 72-75, 79
Wren, size of, 86
Yolk-sac of unhatched chick, 77
Yucca-plant, dependence on an
insect, 128, 135, 142, 158
Zarathustra, his independence of
accidents, 1, 3, 8
Zoothamnium, 100
Zygote, definition, 45 ; fertilized
ovum, 67
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