The Gorilla--His Habitat--Skeleton--Skull--Color--Structural
Peculiarities
In the order of nature the gorilla occupies the second place below man.
His habitat is the lowlands of tropical West Africa, and it is confined
to very narrow limits. The vague lines which bound his realm cannot be
defined with absolute precision, but those generally given in books
that treat of him are not correct. If he ever occupied any part of the
coast north of the equator, he has long since become extinct in that
part; but there is nothing to show that he ever did exist there. So
far as I have been able to trace the lines that define the extent of
his native haunts, they appear to confine him to the low delta country
lying between the equator and the Loango valley along the coast, and
reaching eastward to the interior--an average distance of less than
one hundred miles. The eastern boundary is very irregular. The extreme
limit on the north side is about the Gaboon River, eastward to the
foothills of the Crystal Mountains; thence southward to the Ogowé River
to the vicinity of the mouth of the Nguni; thence up that river twenty
or thirty miles; thence by a zigzag line along the western base of the
dividing lands between the Congo basin and the Atlantic watershed, to
the head-waters of the Chi Loango River, and with that valley to the
coast. Beyond these lines I have found no reliable trace of him, and
along this boundary only now and then is he found, except along the
coast.
I have seen two adult skulls and two infant skulls of the gorilla
that were brought by Mr. Wm. S. Cherry from the Kisanga valley, which
lies on the north side of the middle Congo, into which the Kisanga
River flows. The skulls are the only evidence I have found of this ape
existing so far eastward; but they were said to have come from that
part of the valley lying directly under the equator. Mr. Cherry himself
did not collect them. He secured them from natives, and he does not
claim to have seen any of those apes alive.
There appear to be three centers of gorilla population. The first is in
the basin of Izanga Lake; the second is on the south side of the basin
of Lake Nkami; and the third is in the basin of the lake east of Sette
Kama and west of the Nkami River. The gorilla is rarely, if ever, found
in high or hilly districts. He appears to be restricted to the hummock
lands, which are elevated only a few feet above tide-level. This is
all the more singular from the fact that the ape appears to have a
morbid dislike for water, and it is doubtful whether or not he can
swim. It is true that he has one peculiar characteristic that belongs
to aquatic animals. He has a kind of web between the digits; but its
purpose cannot be to aid in swimming. I have been told that the gorilla
can swim, and the statement may be true; but I have never observed
anything in his habits to confirm this, and I have noted many facts
that controvert it.
I know of no valid reason why he should be confined to the limits
mentioned, unless it be on account of climatic conditions which are
peculiar to this district. South of it the climate along the coast is
much cooler. The country east of it is hilly and comparatively barren.
North of the equator is a land of almost perpetual rain. Within this
district dry and rainy seasons are more equally divided and more
uniform in temperature.
The gorilla appears to be an indigenous product which does not bear
transplanting. He thrives only in a low, hot, and humid region,
infested by malaria, miasma, and fevers. It is doubtful if he can long
survive in a pure atmosphere. The only specimen that I have ever heard
of north of the equator was one on the south side of the Komo River,
which is the north branch of the Gaboon. The point at which I heard of
his being was within a few miles of the equator. I also heard of five
having been seen a few miles southwest from Njole, which is located on
the equator on the north bank of the Ogowé, a little way east of the
Nguni. They were said to be the first and only ones ever seen in that
region within the memory of man. As to their being found between Gaboon
and Cameroon, I find no trace along the coast of one ever having been
seen in that part.
Certain writers have mentioned the fact that, in 1851 and 1852,
gorillas came in great numbers from the interior to the coast. The
fact is that then the gorilla was practically unknown to science. He
had been reported by Ford, Savage, and others, but prior to that time
there are no data to show whether or not they were more numerous
in the years mentioned. There had never been a specimen brought to
civilization. It was about that time that Dr. Ford sent a skeleton
to America, and one had been previously sent to England. Some years
earlier Dr. Savage had announced the existence of such a creature and
had sent sketches of a skull, but it was more than ten years after the
period in question that Paul du Chaillu brought out the first skins of
gorillas and gave detailed accounts of their character, habits, and
geographical distribution. From these facts it is not rash to conclude
that the migrations of 1851 and 1852 are mere matters of fancy.
Gorillas are found in the Ogowé delta, about one degree south latitude;
but not one has ever been known to come from the Crystal Mountains. At
the time above mentioned neither traders nor missionaries had ascended
the Gaboon River above Parrot Island (which is less than twenty miles
from the mouth), except to make a flying trip by canoe. Nothing was
known of those parts except what was learned from the natives, and that
was very little. During my first voyage I went up the river as far as
Nenge Nenge, about seventy-five miles from the coast. At that place I
spent two days with a white trader, who had been stationed there for a
year. I was assured by him that there were no gorillas in that section.
The natives report that they have been found in the lowlands south
of there, in the direction of the Ogowé basin; but their reports are
conflicting, and none of them, so far as I could learn, claims that
they are found north of there, nor in the mountains eastward. I admit
that they may have been found in, and may yet inhabit, the strip of
land between the Gaboon and the Ogowé; but I repeat that there is no
tangible proof that they were ever found north of the Gaboon. With due
respect to Sir Richard Owen and other writers who have never been in
that country, I insist that they are mistaken. It is true that one of
the tribes living north of the Gaboon has a name for this animal; but
it does not follow that the ape lives in that country. The Orungu tribe
has a name for lion, but there is not such a beast within two hundred
miles of their country. Not one of that tribe ever saw a lion.
A number of specimens of gorillas have been secured at Gaboon, but
they have been brought there from far away. It is the chief town of
the colony, and there are more white men there than elsewhere to buy
them. It is not possible for a stranger to ascertain what part of the
country a specimen is brought from. The native hunter will not tell the
truth, lest some one else should find the game and thus deprive him of
its capture and sale. I saw a specimen at Cameroon, and was told it had
been captured in that valley, fifty miles from the coast; but I hunted
up its history and found with absolute certainty that it was captured
near Mayumba, two hundred miles south of Gaboon.
Even with the greatest care in hunting up the history of a specimen,
one may fail, and often does fail, in tracing it to its true source;
but every one, so far, that I have followed up has been brought from
somewhere within the limits I have laid down. Contrary to the statement
of some authorities that these apes “have never been seen on the coast
since 1852,” I assert that by far the greatest number of them are found
near the coast. I do not mean to say that they sit on the sand along
the beach, or bathe in the surf, but they live in the jungle of the low
coast belt. Along the lower Congo the gorilla is known only by name,
and scores of the natives do not know even that. The nearest point to
that river that I have been able to locate the gorilla as a native is
in the territory about sixty or seventy miles northwest of Stanley Pool.
I am much indebted to the late Carl Steckelman, who was an old resident
of the coast, a good explorer, a careful observer, and an extensive
traveler. He was drowned at Mayumba in my presence in October, 1895.
I knew him well and secured from him much information concerning the
gorilla. On a map he traced out for me what he believed to be the south
and southeast limits of the gorilla’s habitat. Not thirty minutes
before the accident in which he lost his life I had closed arrangements
with him to make an expedition from Mayumba to the Congo, near Stanley
Pool, by one route and return by another, but his death prevented the
fulfillment of this plan.
Dr. Wilson, who was the first missionary at Gaboon, located there in
1842. About six years after that time he wrote a lexicon of the native
language. In this the name of the gorilla does not appear at all. If
the ape had been so very common, it is not probable that his name would
have been omitted from this lexicon. Eight years later Dr. Walker, in
a revision of the book, gave the definition, “a monkey larger than a
man.” But he had never seen a specimen of the ape, except the skulls
and a skeleton which had been brought from other parts. It is true
that at Gaboon Dr. Savage first learned about the gorilla and there
secured a skull. From this he made drawings, on which account his name
was attached to that of the animal in natural history. It was still a
few years later that Dr. Ford sent the first skeleton to America, and
Captain Harris sent the first to England. The former skeleton is in the
Museum of Zoölogy at Philadelphia. Both of these specimens may have
come from any place a hundred miles away from Gaboon.
It is possible that at this early date the gorilla may have occupied
the peninsula south of the Gaboon River in greater numbers than he
has since done, because up to that time there had been no demand for
specimens. If this was true at that time, it is not so now; and if
he is not extinct in that part, he is so rare as to make it doubtful
whether or not he is found there at all as a native. In four journeys
along the Ogowé River and the lakes of that valley I made careful
inquiries at many of the towns, and the natives always assured me
that the gorillas lived on the south side of that river. I spent five
days at the village of Moiro, which is located on the north side of
the river and about fifty miles from the coast. There I was told by
the native woodsmen that no gorillas lived on the north side of the
river, but that there were plenty of them along the lakes south of the
river. They said that in the forest back of their town were plenty of
chimpanzees, and that they were sometimes mistaken for gorillas, but
there were absolutely none of the latter in that part.
In view of these and countless other facts I deem it safe to say
that few or no gorillas can be found at any point north of the Ogowé
River; and I doubt if the specimen heard of on the Komo was a genuine
gorilla. The natives sometimes claim to have something of the kind
for sale, in order to get a bonus from some trader, when in truth they
may not have anything of the kind. The only point north of the Ogowé
at which I have had any reason to believe a gorilla was ever found
was in the neighborhood of a small lake called Inenga. This lake is
nearly due west from the mouth of the Nguni River and something more
than a hundred miles from the coast. Certain reports along that part
appeared to have a flavor of truth; but there was no evidence except
the statement of the natives.
In the lake region south of the river they are fairly abundant as far
south as the head-waters of the Rembo, Nkami, and through the low
country of the Esyira tribe; but they are very rare in the remote
forests and unknown in the highlands and plains of that country. South
of the Chi Loango they are quite unknown, and south of the Congo they
are never heard of.
There are no possible means of estimating their number; but they are
not so numerous as has been supposed, and from the reckless slaughter
carried on by the natives in order to secure specimens for white men,
they may ultimately become extinct. Up to this time their ferocity
alone has saved them from such a fate. But the use of improved arms
will soon overcome that barrier.
The skeleton of the gorilla is so nearly the same as that of
the chimpanzee--which has elsewhere been compared to the human
skeleton--that we shall not review the comparison at length; but we
must note one marked feature in the external form of the skull, which
differs alike from other apes and from man.
The skull of the young gorilla is much like that of the chimpanzee and
remains so until it approaches the adult state. At this period the
ridge above the eyes becomes more prominent, and at the same time a
sharp, bony ridge begins to develop along the temples and continues
around the back of the head on that part of the skull called the
occiput. At this point it is intersected by another ridge at right
angles to it. This is called the sagittal ridge. It runs along the top
of the head towards the face; but on the forehead it flattens nearly to
the level of the skull and divides into two very low ridges, which turn
off to a point above the eyes and merge into that ridge. These form a
continuous part of the skull and are not joined to it by sutures. The
mesial crest in a very old specimen rises to the height of nearly two
inches above the surface of the skull, and imparts to it a fierce and
savage aspect; but in the living animal the crests are not seen, as the
depressions between them are filled with large muscles, which make the
head look very much larger than it otherwise would. These crests affect
only the exterior of the skull and do not appear to alter the form or
size of the brain cavity, which is slightly larger in proportion than
that of the chimpanzee. These crests are peculiar to the male gorilla.
The female skull shows no trace of them.
There is at least one case in which the male gorilla has failed to
develop this crest. In the series of skulls found in the cuts given
herewith, No. 6 is that of an adult male gorilla. I know it to be such,
for I dissected the animal and prepared the skeleton for preservation.
He was killed in the basin of Lake Ferran Vaz, not more than three or
four hours’ walk from my cage, and his body was at once brought to me.
A good idea of his size can be obtained by reference to another cut
given herewith. This cut is copied from a photograph taken by me. It
shows some natives in the act of skinning the gorilla.
[Illustration: SKULLS OF GORILLAS--FRONT VIEW (From a Photograph in
Buffalo Museum.)]
[Illustration: SKULLS OF GORILLAS--PROFILE VIEW (From a Photograph in
Buffalo Museum.)]
In this picture the gorilla is sitting flat on the sand; his body is
limp and is somewhat shorter than it was in life. Yet it can be seen
that the top of his head is higher than the hip of the man who is
holding him. In the foreground, on the left of the gorilla, sits the
man who killed him. He is sitting on a log and is thereby a little more
elevated than the gorilla. It did not occur to me to place them side
by side in order to make a comparison. As he sits, the body and head
of this gorilla measure nearly four feet from the base of the spinal
column to the top of the head. I had no means of weighing him, but made
an estimate by lifting him. I estimate that he weighed at least two
hundred and forty pounds. He was not an old specimen, but comparing the
skull with No. 7, in which the crests are well developed, it is found
to be larger, and other things point to the conclusion that he was
older than No. 7.
I am aware that one specimen does not of itself establish anything, but
in this case it shows that the male gorilla does not always develop
the crest. The head of this specimen was surmounted by the red crown
which I have elsewhere described. No. 1, which is the skull of my pet,
Othello, had the same mark. He was captured near the place where No. 6
was killed.
No. 2 is the skull of a female nearly four years old. She had the same
mark. She was also captured in the same basin, but on the opposite
side of the lake. The facial bones of No. 6 show that he had received a
severe blow early in life; but the fragments had knit together, and the
effect could not be seen in the face of the ape while alive.
No. 8 is the skull of a large male from Lake Izanga, which is on the
south side of the Ogowé River, more than a hundred miles from the
coast. This is one of the three centers of population mentioned. I do
not know the history of this specimen. It was presented to me by Mr.
James Deemin, an English trader, with whom I traveled many days on the
Ogowé River, and who extended to me many courtesies.
No. 5 is the skull of an adult female. By comparing it in profile with
No. 6, it will be seen that they resemble each other closely, except
that the muzzle of the latter projects a little more, and the curvature
of the skull across the top is less; but the transverse distance is a
little greater. Nos. 2, 3, 4, and 5 are females; the others are males.
[Illustration: NATIVES SKINNING A GORILLA (From a Photograph.)]
While this series is not complete in either sex, it is an excellent one
for comparative study. I do not know whether or not the heads of those
with the crests were the same color as No. 6, but the _ntyii_, which
I have mentioned as possibly a new specimen of the gorilla, does not
have this crown of red. His ears are also said to be larger than those
of the gorilla, but smaller than the chimpanzee’s. He is reputed to
grow to a larger size than either of them. The skin of the gorilla is a
dull black or mummy color over the body; but over the face it is a jet
black, quite smooth and soft. It looks almost like velvet.
One fact peculiar to this ape is that the palms of both the hands
and the feet are perfectly black. In other animals these are usually
lighter in color than the exposed parts. In most other apes, monkeys,
baboons, and lemurs, as in all races of men, the palms are lighter
than the backs of the hands and feet. The thumb of the gorilla is more
perfect than that of the chimpanzee, yet it is smaller in proportion to
the hand than in man. The hand is very large, but has more the shape of
the hand of a woman than that of a man. The fingers taper in a graceful
manner, but by reason of the web alluded to they appear much shorter
than they really are. It is not really a web in the true sense, but the
integument between the fingers is extended down almost to the second
joint. The forward edge of this is concave when the fingers are spread.
When the fingers are brought together the skin on the knuckles becomes
wrinkled, and the web almost disappears. This is more readily noticed
in the living animal than in the dead. The texture of the skin in the
palms is coarsely granulated, and the palmar lines are indistinct. The
great toe sets at an angle from the side of the foot, thus resembling
a thumb. It has more prehension than the corresponding member of the
hand. The foot is less flexible than the hand, but it has greater
strength and prehension.
At this point I wish to draw attention to one important fact. The
tendons of the foot, which open and close the digits, are imbedded in
the palm in a deep layer of coarse, gristly matter, which forms a pad,
as it were, under the soles of the foot and prevents it from bending.
Therefore it is not possible for a gorilla to sleep on a perch. In
this respect he resembles man more than the chimpanzee does, but it
is quite certain that neither of them has the true arboreal habit.
The gorilla is an expert climber, but he cannot sleep in a tree. In
the hand the tendons which close the fingers are the same length as
the line of the bones, and this permits him to open the fingers to a
straight line, which the chimpanzee cannot do.
One other important point I desire to mention. The muscles in the leg
of the gorilla will not permit the animal to stand or walk erect. The
large muscle at the back of the leg is shorter than the line of the
bones of the leg above and below the knee. When this muscle is brought
to a tension, those bones form an angle of from 130° to 160°, or
thereabouts. So long as the sum of two sides of a triangle is greater
than the other side, a gorilla can never bring his leg into a straight
line. In the infant state, while the muscles are elastic and the bones
less rigid, the leg can be forced nearly straight. The habit of hanging
by the arms and walking with them in a straight line develops the
corresponding muscle in those members so that the bones can be brought
in line and the limbs straightened.
The gorilla can stand upon his feet alone and walk a few steps in that
position; but his motion is very awkward; his knees turn outward,
forming an angle of 40° or 50° on either side of the mesial plane. He
never attempts to walk in this position except at perfect leisure, and
then he holds on to something with his hands.
[Illustration: YOUNG GORILLA WALKING (From a Drawing.)]
The leg of the gorilla from the knee to the ankle is almost the same
in size. In the human leg there is what is called the “calf” of the
leg, but in the apes this is very small. However, there is a tendency
in the ape to develop that feature. In the human species the calf of
the leg appears to belong to the higher types of men. As we descend
from the highest races of mankind this characteristic decreases, and
it almost disappears in the lowest savage. The pygmies and the bushmen
have smaller calves than any other men. It is not to be inferred from
this that apes would ever have this feature developed in them by their
elevation to a higher plane. So long as they remain apes they will
retain this characteristic, which is one of the distinctive features
of their apehood. One thing which makes the calf appear smaller in
the gorilla is the large size of the muscles about the ankle and the
flexibility of that joint. Also the fact that the joint of the knee is
larger in proportion to the leg makes it appear smaller than it really
is. The corresponding parts of the arm are more like those of the human
body.
In a sitting posture the gorilla rests his body upon the ischial bones
and sits with his legs extended or crossed. The chimpanzee usually
squats, resting the ischial bones upon his heels. He sometimes sits,
but more frequently he squats. When in either of these attitudes both
kinds usually fold their arms across their breasts.
The hair of the gorilla is irregular in growth. It is more dense than
that of the chimpanzee, but less uniform in size and distribution.
On the breast it is very sparse, while on the back it is dense and
interspersed with long, coarse hairs. The hair on the arms is long and
coarse. The ground color is black, but the extreme end of the hair
is tipped with pale white. This is so even in early youth. With age
the white encroaches, until in extreme age the animal becomes quite
gray. The top of the head is covered with a growth of short hair. In
certain specimens this crest is of a dark tan color. It looks almost
like a wig. This mark seems to be peculiar to certain localities. It is
uniform among those captured in the Ferran Vaz basin.
A white trader living on Ferran Vaz Lake claims to have seen a gorilla
which was perfectly white. It was said to have been seen on a plain
near the lake in company with three or four others. It was thought to
be an albino. In my opinion it was only a very aged specimen turned
gray. A few of them have been secured that were almost white. It is
not, however, such a shade of white as would be found in an animal
whose normal color is white. I cannot vouch for the color of this ape
seen on the plain, but there must have been something peculiar in it to
attract attention among the natives. They regarded it as something very
extraordinary.
So far, only one species of this ape is known to science; but there
are certain reasons to believe that two species exist. In the forest
regions of Esyira the natives described to me another kind of ape,
which they averred was a half-brother to the gorilla. They know the
gorilla by the native name _njina_, and the other type by the name
_ntyii_. They do not confuse this with the native name _ntyigo_,
which is the name of the chimpanzee. Neither is it a local name for
the _kulu-kamba_. All of those apes are known to the natives. They
described in detail, and quite correctly, the three known kinds of ape.
In addition they gave me a minute account of the appearance and habits
of a fourth kind, which I believe to be another species of the gorilla.
They claim that he is more intelligent and human-like than any one of
the others. They say that his superior wisdom makes him more alert and,
therefore, more difficult to find. He is said always to live in parts
of the forest more remote from human habitation. On my next voyage I
mean to hunt for this new species.
The dental formula of the gorilla is the same as that of man; but the
teeth are larger and stronger, and the canine teeth are developed into
tusks. One thing to be remarked is the great variety of malformations
in the teeth of this animal. It is a rare thing to find among them a
perfect set of teeth, except in infancy. The cause of this deficiency
appears to be violence.
The eyes of the gorilla are large, dark, and expressive, but there
is no trace of white in them. That part of the eye which is white in
man is a dark coffee-brown in the gorilla. It becomes lighter as it
approaches the base of the optic nerve. The taxidermist or the artist
who often furnishes him with a white spot in the corner of his eye does
violence to the subject. Those who pose him with his mouth opened like
a fly-trap, and his arms raised like a lancer, ought to be banished
from good society. It is true that such things lend an aspect of
ferocity to the creature, but they are caricatures of the thing they
mean to portray.
The ears of the gorilla are very small and lie close to the sides of
the head. The model of them is much like the human ear. The lower lip
is massive, and the animal frequently relaxes it, so that a small red
line is visible between the lips. The usual height of the adult male
gorilla, if standing quite erect, is about five feet ten inches. The
tallest specimen that has ever been taken is a trifle more than six
feet two inches.
I shall not pursue the comparison into minute details, but shall leave
that to the specialist, in whose hands it will be treated with more
skill and greater scope. As my especial line of research has been
in the study of the speech and the habits of these animals, I shall
confine myself to that. But the general comparison made is necessary to
a better understanding of these subjects.