Gorilla , the largest of the anthropoid apes, a native of the equatorial region of western Africa, and first introduced to the scientific world by Dr. T. S. Savage in 1847. There were vague reports by voyagers and travellers of the existence in Africa of a quadrumanous animal larger than the chimpanzee, and there were in museums portions of a creature since ascertained to be the gorilla; but naturalists had their attention first called to it by the paper of Dr. Savage in vol. v. of the "Boston Journal of Natural History," in which he described the external characters and habits, and Prof. Jeffries Wyman described four crania and several parts of the skeleton. Dr. Savage described it as troglodytes gorilla; Prof. Owen called it T. Savagei, retaining it in the same genus with the chimpanzee; Geoffroy Saint-Hilaire established for it the genus gorilla in 1852, and in 1853 gave it the name of G. gina, which is the best known, though G. Savagei has a prior claim. The common names of the gorilla among the natives of the region where it is found are engeena, geena, and engeela.
There are specimens of the animal, more or less complete, in the collections at Philadelphia, Boston, London, and Paris; and Du Chaillu, on his return to the United States in August, 1859, from the country about the Gaboon river, brought with him several complete specimens, male and female, both skins and skeletons, in excellent preservation, most of which are now in the London collections. Du Chaillu is the first white man who killed a gorilla with his own hand, or who had an opportunity of studying its habits in its native forests. - The skull of the male is longer and wider, but less heavy, than that of man, and the capacity of the cavity which contains the brain is less than one half of that of the most degraded human races. The most striking peculiarity is the great development of the interparietal and occipital crests and the ridges over the orbits, which give an angular outline to the skull, resembling the orangs in the first and the chimpanzee in the latter character; there is a great thickness of the orbital walls, with much space between the orbits, and a prominence on the inner wall directed outward; a noteworthy character is the coalescence of the nasal bones above, with a median suture on their lower half, the upper portion ascending above the nasal processes of the superior maxillary and becoming contracted between them, slightly projecting as in man; the crests are much less in the female.
The cranial crests, wide zygomatic arches, and massive lower jaw give indication of the powerful muscles. The dental formula is the same as in man and the higher quadrumana; the canines are enormous, the ineisors very wide, the lateral ones being more pointed, and the lower molars have five tubercles instead of four. The bones of the trunk and extremities are remarkable for their size and strength: the length of the cervical spines is such that the nape is more prominent than the back of the head; the scapulas and bones of the arm indicate the attachment of muscles in comparison with which man's seem like those of a child. The expression of the face is scowling; the nose is very flat and widely open; the ears are small; the eyes are much sunk in the head, and the lashes are short and thick; the mouth is very wide, the lips large and thin, the lower one pendulous and very movable, the chin short and receding, and the whole muzzle prominent; the face is transversely wrinkled and black. The chest is capacious, the shoulders very wide, and the abdomen everywhere projecting.
The limbs are greatly developed and of immense strength; the arms are longer than in the chimpanzee, reaching far down the leg, but according to Owen, whose observations are generally confirmed by the specimens of Du Chaillu, the arms do not extend so low as the knee; while the arm and forearm are longer than in the chimpanzee, the hand is shorter, wider, and more human in its carpal and metacarpal portions and the lateral position of the thumb; from the length of the palm the fingers appear short and thick as if swollen; they are also less free, as the posterior portion of the three intermediate fingers is covered by the undivided integument. There is very little appearance of wrist, the circumference at this part being twice that of a strong man's; the fingers taper to a point, are not arched, and the nails are flat and relatively small; the fingers are about twice the circumference of man's, and the skin of the middle joint is callous from the habit of the animal of applying these surfaces to the ground when it adopts a favorite way of progression by swinging its body forward supported by and between the hands; the thumb is short, and not more than half the size of the fore finger.
The posterior extremities are occasionally used alone in standing and in progression; the thigh is relatively short, and of a nearly uniform size, in its middle portion not surpassing in circumference the same part in man; the leg increases in thickness from below the knee to the ankle; the tendinous portion of the muscles is developed more than the fleshy, with a great gain in strength. The foot is longer than the hand, and is humanlike also in having the three intermediate toes about the same length, and partly united at their base by the integuments; the gorilla is essentially quadrumanous, and the posterior thumbs are largely developed, widely separated from the toes, to which they are easily opposed, and well calculated for prehension. The genus gorilla was established by Geoffroy Saint-Hilaire on the following characters principally : the head rounded in the young, very much elongated and depressed in the adult, with very prominent cranial crests; the peculiar conformation of the organs of sense, above detailed; the gigantic size; the proportions of the limbs, and the characters of the hands and feet; and the peculiarities of the teeth.
It seems sufficiently distinct from troglodytes ni-ger. It is not easy to determine the precise position of the gorilla in the quadrumanous series; in the structure of the hand and foot it comes nearer to man than the chimpanzee does; in the canines it would seem to be below even the orangs; and in the proportion of the arm and forearm it is below the chimpanzee. The very indefiniteness of its position is another argument for its separation as a genus among the quadrumana. The adult male gorilla is from 5 to 6 ft. high in its natural altitude, though after death it may be stretched beyond this; most specimens are under 6 ft., on account of the relative shortness and gene-rally flexed position of the legs; it far surpasses man in the dimensions of the head, neck, body, and arms, and in the width of the shoulders; some are said to measure from 7 to 9 ft. from the end of one outstretched hand to that of the other; one of Du Chaillu's specimens measures 8 ft. 11 in. The general color of the hair, which is coarse and about 2 in. long on the arms, an inch on the belly, and quite short on the back and legs, is gray inclining to black. There is a black stripe about 2 1/2 in. wide extending diagonally down the sides from behind the shoulder to the belly, which is entirely black.
On the upper portion of the back the hair is very thin; old ones are bare in that part. On the arms the hair is black, and reversed from the wrist to the elbow; the chest is nearly bare; there are a few white hairs in the anal region; the face, hands, and feet are black; the hands are hairy as far as the division of the fingers, the palms naked and callous; the head has generally a reddish tint; on the whole the male would be called grayish and the female blackish. The young differ greatly from the adults in the shape of the head, and the females are less ferocious-looking as well as much smaller than the males. - The gorilla is found on the W. coast of Africa, both N. and S. of the equator, but especially in the wooded districts of the interior near the head waters of the Gaboon river, and along the Muni river as far E. as the Crystal mountains. It is principally an inhabitant of the woods, but though the structure of its four hands seems well adapted to climbing on trees, it is very rare that a female or a young male is seen on them - the old males never; its favorite mode of progression is on all fours, in a shuffling manner and rolling from side to side, but with its head always erect and its face looking forward; on account of the greater length of the arms it stoops less than the chimpanzee, and is fond of thrusting these forward, with the flexed fingers on the ground, and of giving its body a half jumping, half swinging motion forward between them; when it assumes the erect posture, it flexes the arms upward or crosses them on the nape in order to counterbalance the tendency of the trunk to fall forward.
Gorillas are generally seen in troops of five, four females and one male, but the old males are occasionally met wandering alone; though living in the same neighborhood as the chimpanzees, they do not associate with them. Their strength is enormous, not only in the jaws, which are able to crush the barrel of a musket, but in the hands and feet, which they use in common with their canines in attack and defence; they are able to break with ease trees three or four inches in diameter. The males are exceedingly ferocious, generally attacking man and animals intruding upon their haunts; if wounded, they are more terrible than the lion, and in this event the hunter's death is sure and speedy if his hand trembles or his gun misses fire. They approach the enemy standing, advancing a few steps at a time, pausing to beat their breasts with both hands, and roaring terribly. When near enough, they spring upon him, and destroy him with their powerful hands. One of Du Chaillu's men was eviscerated by a single blow. The story of their carrying clubs is untrue. They are perfectly untamable, in this respect differing from the chimpanzee, which, in youth at least, appreciates kind treatment.
When living in troops they are shy and difficult to approach, but when mated or alone they almost invariably offer battle, and are then the most terrible of animals. When living near villages, they sometimes come at daybreak to eat the plantains and sugar cane of the natives; besides these they eat nuts, berries, fruits of the oil palm and banana, the acid pulp of the amomum, the white portions of the leaves of the pineapple, and roots. Unlike the chimpanzee, the gorilla makes no shelter for itself. In intelligence it is considerably inferior to the chimpanzee. It exhibits great fondness for its young, of which it has one at a time. The reports of its visiting villages and carrying off negresses into the woods are mere fables. It is generally mute, but sometimes amuses itself by a sort of roaring, which, beginning low, increases till the forest echoes with its reverberations. When about to attack its enemies it gives a terrific yell, which resounds far and wide. The negroes of the interior are very fond of eating the flesh of gorillas as well as of chimpanzees and monkeys.
Among the coast tribes on the other hand, it is considered an abomination to eat the flesh of either the gorilla or the chimpanzee, on account of their resemblance to man.