The Chimpanzee--The Name--Two Species--The Kulu-Kamba
Distribution--Color and Complexion
Next to man the chimpanzee occupies the highest plane in the scale of
nature. His mental and social traits, together with his physical type,
assign him to this place.
In his distribution he is confined to equatorial Africa. His habitat,
roughly outlined, is from the fourth parallel north of the equator
to the fifth parallel south of it, along the west coast, and extends
eastward a little more than halfway across the continent. His range
cannot be defined with precision, for its exact limits are not yet
known. Its boundary on the north is defined by the Cameroon valley,
slightly curving towards the north; but its extent eastward is a matter
of some doubt. He does not appear to be found anywhere north of that
river, and it is quite certain that the few specimens attributed to the
north coast of the Gulf of Guinea do not belong to that territory. On
the south the boundary of his habitat starts from the coast, at a point
near the fifth parallel, curves slightly northward, crosses the Congo
near Stanley Pool, pursues a northeasterly course to about the middle
of the Congo State, and again curves southward across the Upper Congo,
not far from the north end of Lake Tanganyika. Its limits appear to
conform more to isothermal lines than to the rigid lines of geography.
Specimens are sometimes secured by collectors beyond these limits, but,
so far as I have been able to ascertain, they have been captured within
the territory thus bounded. There are several centers of population.
This ape is not strictly confined to any definite topography, but
occupies alike the upland forests or the low basin lands.
In one section he is known to the natives by one name, and in another
by a name entirely different. The name _chimpanzee_ is of native
origin. In the Fiote tongue the name of the ape is _chimpan_, which
is a slight corruption of the true name. It is properly a compound
word. The first syllable is from the Fiote word _tyi_, which white
men erroneously pronounce like “chee.” It means “small,” or inferior,
and it is found in many of the native compounds. The last syllable is
from _mpa_, a bushman; hence the word literally means, in the Fiote
tongue, “a small bushman,” or inferior race. The name really implies
the idea of a lower order of human being. Among other tribes a common
name of the ape is _ntyigo_. The latter is derived from the Mpongwe
word _ntyia_, blood, race, or breed, and the word _iga_, the forest. It
literally means the “breed of the forest.” The same idea of its being
a low type of humanity is involved in the two names. Both convey the
oblique suggestion that the animal is more nearly allied to man than
other animals are.
There are two distinct types of this ape. They are now regarded as
two species. One of them is distributed throughout the entire habitat
described, while the other is only known south of the equator and
between the second and fifth parallels north of the Congo and west
of Stanley Pool. Both kinds are found within this district, but the
variety which is confined to that region is called, by the tribes that
know the ape, the _kulu-kamba_, in contradistinction from the other
kind known as _ntyigo_. This name is derived from _kulu_, the onomatope
of the sound made by the animal and the native verb, _kamba_, to speak;
hence the name literally means “the thing that speaks kulu.”
In certain respects the common variety differs from the _kulu-kamba_
in a degree that would indicate that they belong to distinct species;
but the skulls and the skeletons are so nearly alike that no one can
identify them from the skeletons alone. In life, however, it is not
difficult to distinguish them. The _ntyigo_ has a longer face and more
prominent nose than the _kulu_. His complexion is of all shades of
brown, from a light tan to a dark, dingy, mummy color. He has a thin
coat of short, black hair, which is often erroneously described as
brown; but that effect is due to the blending of the color of his skin
with that of his suit. In early life his hair is quite black, but in
advanced age the ends are tipped with a dull white, giving them a dingy
gray color. The change is due to the same causes that produce gray
hairs on the human body. But there is one point in which they greatly
differ. The entire hair of the human becomes white with age, while only
the outer end of it does so in the chimpanzee. In the human one hair
becomes white, while others retain their natural color; but in this
ape all the hairs appear to undergo the same change. In very aged
specimens the outer part of the hair often assumes a dirty, brownish
color. This is due to the want of vascular action to supply the color
pigment. The same effect is often seen in preserved specimens, for the
same reason that the hair of an Egyptian mummy is brown, though in life
it had been, doubtless, a jet black. In this ape the hair is uniformly
black, except the small tuft of white at the base of the spinal column
and a few white hairs on the lower lip and the chin. I have examined
about sixty living specimens, and I have never found any other color
among them, except from the cause mentioned. The normal color of both
sexes is the same. The _kulu_ has, as a rule, but little hair on the
top of the head; but that on the back of it and on the neck is much
longer than elsewhere on the body, and on these parts it is longer than
that on other apes.
Much stress is laid by some writers on the bald head of one ape and the
parted hair on the head of another. These features cannot be relied
upon as having any specific meaning, unless there are as many species
as there are apes. Sometimes a specimen has no hair on the crown of the
head, while another differs from it in this respect alone by having
a suit of hair more or less dense; and yet in every other respect
they are alike. Some of them have their hair growing almost down to
the eyebrows, and all hairs appear to diverge from a common center,
like the radii of a sphere; another of the same species may have the
hair parted in the middle as neatly as if it had been combed; another
may have it in wild disorder. The same thing is noticed in certain
monkeys, and it is equally true of the human being. As a factor in
classifying, it signifies nothing. It may be remarked that the _kulu_
is inclined to have but little hair upon the crown of the head.
Between the two species there is a close alliance. The males differ
more than the females. This is especially true in the structure of
certain organs. The face of the young _ntyigo_ is free from hairs, but
in the adult state there is in both sexes a tendency to the growth of
a light down upon the cheeks. The color of the skin is not uniform
in all parts of the body. This is especially true of the face. Some
specimens have patches of dark color set in a lighter ground. Sometimes
certain parts of the face are dark and other parts light. I have seen
one specimen quite freckled. It is said by some that the skin is light
in color when young, and becomes darker with age; but I find no reason
to believe that such is the case. It is true that the skin darkens a
few shades as the cuticle hardens, but there is no transition from one
color to another, and this slight change of shade is chiefly on the
exposed parts.
The _kulu_ has a short, round face, much like that of a human. In early
life it is quite free from hairs, but, like the other, a slight down
appears with age. He has on his body a heavy suit of black hair. It
is coarser and longer than that of the _ntyigo_. It is also inclined
to wave, thus having a fluffy aspect. The color is jet black, except
a small tuft of white about the base of the spine. I have seen two in
which this tuft was perfectly black. The skin varies in color less than
in the _ntyigo_, and the darker shades are seldom found. The eyes are a
shade darker, and in both species the parts of the eye which are white
in man are brown in them. But this gradually shades off into a yellow
near the base of the optic nerve. As a rule, the _kulu_ has a clear,
open visage, with a kindly expression. It is confiding and affectionate
to a degree beyond any other animal. It is more intelligent than its
_confrère_, and displays the faculty of reason almost like a human
being.
One important point in which these two types of ape differ is in the
scope and quality of their voices. The _kulu_ makes a greater range of
vocal sounds. Some of them are soft and musical; but those uttered by
the _ntyigo_ are fewer in number and harsher in quality. One of these
sounds resembles the bark of a dog, and another is a sharp, screaming
sound. The _kulu_ evinces a certain sense of gratitude, while the
_ntyigo_ appears to be almost devoid of that sentiment. There are many
traits in which they differ, but human beings, even within the same
family circle, also differ in these qualities. The points in which they
coincide are many, and, after a brief review of them, we may consider
the question of making two species of them or assigning them to the
same.
The skeletons--as we have noted--are the same in form, size, and
proportion. Their muscular, nervous, and veinous systems are for the
most part the same. The character of their food and the mode of eating
are the same in each. In captivity they appear to regard each other as
one of their own kind; but whether they inter-cross or not remains to
be learned.
Such is the sum of the likenesses and the differences between the two
extreme types of this genus. With so many points in common, and so
few in which they differ, it is a matter of serious doubt whether they
can be said to constitute two distinct species or only two varieties
of a common species. This doubt is further emphasized by the fact that
all the way between these two extremes are gradations of intermediate
types, so that it is next to impossible to say where one ends and
another begins.
In view of all these facts, I believe them to be two well-defined
varieties of the same species. They are the white man and the negro
of a common stock. They are the patrician and the plebeian of one
race, or the nobility and the yeomanry of one tribe. They are like
different phases of the same moon. The _kulu-kamba_ is simply a high
order of chimpanzee. It is quite true that two varieties of one species
usually have the same vocal characteristics, and this appears to be the
strongest point in favor of assigning them to separate species, but it
is not impossible that even this may be waived. Leaving this question
for others to decide as they find the evidence to sustain them, we
shall for the present regard them as one kind, and consider their
physical, social, and mental characteristics.
Whether they are all of one species, or divided into many, the same
habits, traits, and modes of life prevail throughout the entire group,
so that one description will apply to all, so far as we have to deal
with them as a whole. Elsewhere will be related certain incidents which
apply to individuals of the two kinds mentioned; but in treating of
them collectively the term _chimpanzee_ is meant to include the whole
group, except where it is otherwise specified.