(see "Proc. Linn. Soc." Zool. vol. vii.) show that out of the large
number of 301 species collected in Celebes, 190 (or nearly two-thirds)
are absolutely restricted to it, although Borneo on one side, and the
various islands of the Moluccas on the other, were equally well explored
by me; and no less than twelve of the genera are not found in any other
island of the archipelago. I have shown in the present essay that, in
the Papilionidae, it has far more species of its own than any other
island, and a greater proportion of peculiar species than many of the
large groups of islands in the archipelago--and that it gives to a large
number of the species and varieties which inhabit it, 1st, an increase
of size, and, 2nd, a peculiar modification in the form of the wings,
which stamp upon the most dissimilar insects a mark distinctive of their
common birth-place.
What, I would ask, are we to do with phenomena such as these? Are we to
rest content with that very simple, but at the same time very
unsatisfying explanation, that all these insects and other animals were
created exactly _as_ they are, and originally placed exactly _where_
they are, by the inscrutable will of their Creator, and that we have
nothing to do but to register the facts and wonder? Was this single
island selected for a fantastic display of creative power, merely to
excite a childlike and unreasoning admiration? Is all this appearance of
gradual modification by the action of natural causes--a modification the
successive steps of which we can almost trace--all delusive? Is this
harmony between the most diverse groups, all presenting analogous
phenomena, and indicating a dependence upon physical changes of which we
have independent evidence, all false testimony? If I could think so, the
study of nature would have lost for me its greatest charm. I should
feel as would the geologist, if you could convince him that his
interpretation of the earth's past history was all a delusion--that
strata were never formed in the primeval ocean, and that the fossils he
so carefully collects and studies are no true record of a former living
world, but were all created just as they now are, and in the rocks where
he now finds them.
I must here express my own belief that none of these phenomena, however
apparently isolated or insignificant, can ever stand alone--that not the
wing of a butterfly can change in form or vary in colour, except in
harmony with, and as a part of the grand march of nature. I believe,
therefore, that all the curious phenomena I have just recapitulated, are
immediately dependent on the last series of changes, organic and
inorganic, in these regions; and as the phenomena presented by the
island of Celebes differ from those of all the surrounding islands, it
can, I conceive, only be because the past history of Celebes has been,
to some extent, unique and different from theirs. We must have much more
evidence to determine exactly in what that difference has consisted. At
present, I only see my way clear to one deduction, viz., that Celebes
represents one of the oldest parts of the archipelago; that it has been
formerly more completely isolated both from India and from Australia
than it is now, and that amid all the mutations it has undergone, a
relic or substratum of the fauna and flora of some more ancient land has
been here preserved to us.
It is only since my return home, and since I have been able to compare
the productions of Celebes side by side with those of the surrounding
islands, that I have been fully impressed with their peculiarity, and
the great interest that attaches to them. The plants and the reptiles
are still almost unknown; and it is to be hoped that some enterprising
naturalist may soon devote himself to their study. The geology of the
country would also be well worth exploring, and its newer fossils would
be of especial interest as elucidating the changes which have led to its
present anomalous condition. This island stands, as it were, upon the
boundary-line between two worlds. On one side is that ancient Australian
fauna, which preserves to the present day the facies of an early
geological epoch; on the other is the rich and varied fauna of Asia,
which seems to contain, in every class and order, the most perfect and
highly organised animals. Celebes has relations to both, yet strictly
belongs to neither: it possesses characteristics which are altogether
its own; and I am convinced that no single island upon the globe would
so well repay a careful and detailed research into its past and present
history.
_Concluding Remarks._
In writing this essay it has been my object to show how much may, under
favourable circumstances, be learnt by the study of what may be termed
the external physiology of a small group of animals, inhabiting a
limited district. This branch of natural history had received little
attention till Mr. Darwin showed how important an adjunct it may become
towards a true interpretation of the history of organized beings, and
attracted towards it some small share of that research which had before
been almost exclusively devoted to internal structure and physiology.
The nature of species, the laws of variation, the mysterious influence
of locality on both form and colour, the phenomena of dimorphism and of
mimicry, the modifying influence of sex, the general laws of
geographical distribution, and the interpretation of past changes of the
earth's surface, have all been more or less fully illustrated by the
very limited group of the Malayan Papilionidae; while, at the same time,
the deductions drawn therefrom have been shown to be supported by
analogous facts, occurring in other and often widely-separated groups of
animals.
V.
ON INSTINCT IN MAN AND ANIMALS.
The most perfect and most striking examples of what is termed instinct,
those in which reason or observation appear to have the least influence,
and which seem to imply the possession of faculties farthest removed
from our own, are to be found among insects. The marvellous constructive
powers of bees and wasps, the social economy of ants, the careful
provision for the safety of a progeny they are never to see manifested
by many beetles and flies, and the curious preparations for the pupa
state by the larvae of butterflies and moths, are typical examples of
this faculty, and are supposed to be conclusive as to the existence of
some power or intelligence, very different from that which we derive
from our senses or from our reason.
_How Instinct may be best Studied._
Whatever we may define instinct to be, it is evidently some form of
mental manifestation, and as we can only judge of mind by the analogy of
our own mental functions and by observation of the results of mental
action in other men and in animals, it is incumbent on us, first, to
study and endeavour to comprehend the minds of infants, of savage men,
and of animals not very far removed from ourselves, before we pronounce
positively as to the nature of the mental operations in creatures so
radically different from us as insects. We have not yet even been able
to ascertain what are the senses they possess, or what relation their
powers of seeing, hearing, and feeling have to ours. Their sight may far
exceed ours both in delicacy and in range, and may possibly give them
knowledge of the internal constitution of bodies analogous to that which
we obtain by the spectroscope; and that their visual organs do possess
some powers which ours do not, is indicated by the extraordinary
crystalline rods radiating from the optic ganglion to the facets of the
compound eye, which rods vary in form and thickness in different parts
of their length, and possess distinctive characters in each group of
insects. This complex apparatus, so different from anything in the eyes
of vertebrates, may subserve some function quite inconceivable by us, as
well as that which we know as vision. There is reason to believe that
insects appreciate sounds of extreme delicacy, and it is supposed that
certain minute organs, plentifully supplied with nerves, and situated in
the subcostal vein of the wing in most insects, are the organs of
hearing. But besides these, the Orthoptera (such as grasshoppers, &c.)
have what are supposed to be ears on their fore legs, and Mr. Lowne
believes that the little stalked balls, which are the sole remnants of
the hind wings in flies, are also organs of hearing or of some analogous
sense. In flies, too, the third joint of the antennae contains thousands
of nerve-fibres, which terminate in small open cells, and this Mr. Lowne
believes to be the organ of smell, or of some other, perhaps new, sense.
It is quite evident, therefore, that insects may possess senses which
give them a knowledge of that which we can never perceive, and enable
them to perform acts which to us are incomprehensible. In the midst of
this complete ignorance of their faculties and inner nature, is it wise
for us to judge so boldly of their powers by a comparison with our own?
How can we pretend to fathom the profound mystery of their mental
nature, and decide what, and how much, they can perceive or remember,
reason or reflect! To leap at one bound from our own consciousness to
that of an insect's, is as unreasonable and absurd as if, with a pretty
good knowledge of the multiplication table, we were to go straight to
the study of the calculus of functions, or as if our comparative
anatomists should pass from the study of man's bony structure to that of
the fish, and, without any knowledge of the numerous intermediate forms,
were to attempt to determine the homologies between these distant types
of vertebrata. In such a case would not error be inevitable, and would
not continued study in the same direction only render the erroneous
conclusions more ingrained and more irremovable.
_Definition of Instinct._
Before going further into this subject, we must determine what we mean
by the term instinct. It has been variously defined as--"disposition
operating without the aid of instruction or experience," "a mental power
totally independent of organization," or "a power enabling an animal to
do that which, in those things man can do, results from a chain of
reasoning, and in things which man cannot do, is not to be explained by
any efforts of the intellectual faculties." We find, too, that the word
instinct is very frequently applied to acts which are evidently the
result either of organization or of habit. The colt or calf is said to
walk instinctively, almost as soon as it is born; but this is solely due
to its organization, which renders walking both possible and pleasurable
to it. So we are said instinctively to hold out our hands to save
ourselves from falling, but this is an acquired habit, which the infant
does not possess. It appears to me that instinct should be defined
as--"the performance by an animal of complex acts, absolutely without
instruction or previously-acquired knowledge." Thus, acts are said to be
performed by birds in building their nests, by bees in constructing
their cells, and by many insects in providing for the future wants of
themselves or their progeny, without ever having seen such acts
performed by others, and without any knowledge of why they perform them
themselves. This is expressed by the very common term "blind instinct."
But we have here a number of assertions of matters of fact, which,
strange to say, have never been proved to be facts at all. They are
thought to be so self-evident that they may be taken for granted. No
one has ever yet obtained the eggs of some bird which builds an
elaborate nest, hatched these eggs by steam or under a quite distinct
parent, placed them afterwards in an extensive aviary or covered garden,
where the situation and the materials of a nest similar to that of the
parent birds may be found, and then seen what kind of nest these birds
would build. If under these rigorous conditions they choose the same
materials, the same situation, and construct the nest in the same way
and as perfectly as their parents did, instinct would be proved in their
case; now it is only assumed, and assumed, as I shall show further on,
without any sufficient reason. So, no one has ever carefully taken the
pupae of a hive of bees out of the comb, removed them from the presence
of other bees, and loosed them in a large conservatory with plenty of
flowers and food, and observed what kind of cells they would construct.
But till this is done, no one can say that bees build without
instruction, no one can say that with every new swarm there are no bees
older than those of the same year, who may be the teachers in forming
the new comb. Now, in a scientific inquiry, a point which can be proved
should not be assumed, and a totally unknown power should not be brought
in to explain facts, when known powers may be sufficient. For both these
reasons I decline to accept the theory of instinct in any case where all
other possible modes of explanation have not been exhausted.
_Does Man possess Instincts._
Many of the upholders of the instinctive theory maintain, that man has
instincts exactly of the same nature as those of animals, but more or
less liable to be obscured by his reasoning powers; and as this is a
case more open to our observation than any other, I will devote a few
pages to its consideration. Infants are said to suck by instinct, and
afterwards to walk by the same power, while in adult man the most
prominent case of instinct is supposed to be, the powers possessed by
savage races to find their way across a trackless and previously unknown
wilderness. Let us take first the case of the infant's sucking. It is
sometimes absurdly stated that the new-born infant "seeks the breast,"
and this is held to be a wonderful proof of instinct. No doubt it would
be if true, but unfortunately for the theory it is totally false, as
every nurse and medical man can testify. Still, the child undoubtedly
sucks without teaching, but this is one of those _simple_ acts dependent
upon organization, which cannot properly be termed instinct, any more
than breathing or muscular motion. Any object of suitable size in the
mouth of an infant excites the nerves and muscles so as to produce the
act of suction, and when at a little later period, the will comes into
play, the pleasurable sensations consequent on the act lead to its
continuance. So, walking is evidently dependent on the arrangement of
the bones and joints, and the pleasurable exertion of the muscles, which
lead to the vertical posture becoming gradually the most agreeable one;
and there can be little doubt that an infant would learn of itself to
walk, even if suckled by a wild beast.
_How Indians travel through unknown and trackless Forests._
Let us now consider the fact, of Indians finding their way through
forests they have never traversed before. This is much misunderstood,
for I believe it is only performed under such special conditions, as at
once to show that instinct has nothing to do with it. A savage, it is
true, can find his way through his native forests in a direction in
which he has never traversed them before; but this is because from
infancy he has been used to wander in them, and to find his way by
indications which he has observed himself or learnt from others. Savages
make long journeys in many directions, and, their whole faculties being
directed to the subject, they gain a wide and accurate knowledge of the
topography, not only of their own district, but of all the regions round
about. Every one who has travelled in a new direction communicates his
knowledge to those who have travelled less, and descriptions of routes
and localities, and minute incidents of travel, form one of the main
staples of conversation round the evening fire. Every wanderer or
captive from another tribe adds to the store of information, and as the
very existence of individuals and of whole families and tribes, depends
upon the completeness of this knowledge, all the acute perceptive
faculties of the adult savage are devoted to acquiring and perfecting
it. The good hunter or warrior thus comes to know the bearing of every
hill and mountain range, the directions and junctions of all the
streams, the situation of each tract characterized by peculiar
vegetation, not only within the area he has himself traversed, but for
perhaps a hundred miles around it. His acute observation enables him to
detect the slightest undulations of the surface, the various changes of
subsoil and alterations in the character of the vegetation, that would
be quite imperceptible to a stranger. His eye is always open to the
direction in which he is going; the mossy side of trees, the presence of
certain plants under the shade of rocks, the morning and evening flight
of birds, are to him indications of direction, almost as sure as the sun
in the heavens. Now, if such a savage is required to find his way across
this country in a direction in which he has never been before, he is
quite equal to the task. By however circuitous a route he has come to
the point he is to start from, he has observed all the bearings and
distances so well, that he knows pretty nearly where he is, the
direction of his own home and that of the place he is required to go to.
He starts towards it, and knows that by a certain time he must cross an
upland or a river, that the streams should flow in a certain direction,
and that he should cross some of them at a certain distance from their
sources. The nature of the soil throughout the whole region is known to
him, as well as all the great features of the vegetation. As he
approaches any tract of country he has been in or near before, many
minute indications guide him, but he observes them so cautiously that
his white companions cannot perceive by what he has directed his course.
Every now and then he slightly changes his direction, but he is never
confused, never loses himself, for he always feels at home; till at last
he arrives at a well-known country, and directs his course so as to
reach the exact spot desired. To the Europeans whom he guides, he seems
to have come without trouble, without any special observation, and in a
nearly straight unchanging course. They are astonished, and ask if he
has ever been the same route before, and when he answers "No," conclude
that some unerring instinct could alone have guided him. But take this
same man into another country very similar to his own, but with other
streams and hills, another kind of soil, with a somewhat different
vegetation and animal life; and after bringing him by a circuitous route
to a given point, ask him to return to his starting place, by a straight
line of fifty miles through the forest, and he will certainly decline to
attempt it, or, attempting it, will more or less completely fail. His
supposed instinct does not act out of his own country.
A savage, even in a new country, has, however, undoubted advantages,
from his familiarity with forest life, his entire fearlessness of being
lost, his accurate perception of direction and of distance, and he is
thus able very soon to acquire a knowledge of the district that seems
marvellous to a civilized man; but my own observation of savages in
forest countries has convinced me, that they find their way by the use
of no other faculties than those which we ourselves possess. It appears
to me, therefore, that to call in the aid of a new and mysterious power
to account for savages being able to do that which, under similar
conditions, we could almost all of us perform, although perhaps less
perfectly, is almost ludicrously unnecessary.
In the next essay I shall attempt to show, that much of what has been
attributed to instinct in birds, can be also very well explained by
crediting them with those faculties of observation, memory, and
imitation, and with that limited amount of reason, which they
undoubtedly exhibit.
VI.
THE PHILOSOPHY OF BIRDS' NESTS.
_Instinct or Reason in the Construction of Birds' Nests._
Birds, we are told, build their nests by _instinct_, while man
constructs his dwelling by the exercise of _reason_. Birds never change,
but continue to build for ever on the self-same plan; man alters and
improves his houses continually. Reason advances; instinct is
stationary.
This doctrine is so very general that it may almost be said to be
universally adopted. Men who agree on nothing else, accept this as a
good explanation of the facts. Philosophers and poets, metaphysicians
and divines, naturalists and the general public, not only agree in
believing this to be probable, but even adopt it as a sort of axiom that
is so self-evident as to need no proof, and use it as the very
foundation of their speculations on instinct and reason. A belief so
general, one would think, must rest on indisputable facts, and be a
logical deduction from them. Yet I have come to the conclusion that not
only is it very doubtful, but absolutely erroneous; that it not only
deviates widely from the truth, but is in almost every particular
exactly opposed to it. I believe, in short, that birds do _not_ build
their nests by instinct; that man does _not_ construct his dwelling by
reason; that birds do change and improve when affected by the same
causes that make men do so; and that mankind neither alter nor improve
when they exist under conditions similar to those which are almost
universal among birds.
_Do Men build by Reason or by Imitation?_