[Illustration: Fig. 62.--The home of the gorilla.] The gorilla lives in a society consisting of male and female and their young of varying ages, and the family group inhabits the recesses of the forest.[110] According to von Koppenfels, they frequent the same sleeping-place not more than three or four times consecutively, and usually spend the night wherever they happen to be when night comes on. Koppenfels differs from other narrators in the assertion that the gorilla constructs a bed for his night lair upon the trees. He chooses for this purpose a full-grown tree, not more than 0·30 m. in thickness, breaks and bends the branches together at a height of from five to six metres from the ground, and covers them with the twigs he has torn off, or with the leaf-moss, which grows scantily in this part of Africa. The male animal spends the night crouching at the foot of the tree, against which he places his back, and thus protects the female and their young, which are in the nest above, from the nocturnal attacks of leopards, which are always ready to devour all species of apes. In the daytime the gorillas roam through the tracts of forest which surround their temporary sleeping-places, in order to seek for food. In walking they place the backs of their closed fingers on the ground, or more rarely support themselves on the flat palm, while the flat soles of the feet are also in contact with the ground. The toes are generally extended, and a little separated from each other, but occasionally they are doubled under. Their gait, as Huxley justly observes, is tottering; the movement of the body, which is never in an upright position as in man, but bent forward, rolls to some extent from one side to another. As their arms are longer than those of the chimpanzee, they do not reach out so much; but the gorilla also throws his arms forward, sets his hands upon the ground, then gives a half-swinging, half-springing motion to his body. When assuming the position for walking, the body is much sloped, and its great bulk is so balanced as to bend the arms upwards. In spite of his apparently clumsy and unwieldy form, the gorilla, like the bear, displays great bodily dexterity. He is a very skilful climber, and, as Koppenfels asserts, when ranging from tree to tree, he will go to their very tops. He first tries whether the branches will bear his weight, and if one branch is not strong enough, he makes use of three or four at once. He will also run along the branches on all fours, stepping warily. Koppenfels saw a full-grown animal, as danger approached, spring down from a tree which was thirty or forty feet high, and then hastily crash through the brushwood. All Huxley’s informants concur in the assertion that there is only one adult male attached to each group. As soon as the young male reaches maturity, a conflict for the mastery takes place, and, after his rival is killed or driven away, the stronger animal becomes the head of the community.