The second species of anthropoid apes is the chimpanzee. The full-grown animal of this species is smaller than the adult gorilla. An aged male chimpanzee has broad, rather rounded shoulders, a powerful chest, long muscular arms reaching to the knees, and a long hand, which seems to be very slender in comparison with that of the gorilla. Like the latter animal, he is a denizen of forests, and subsists on wild fruits of various kinds. He lives either in separate families or in small groups of families. Where he inhabits the forest regions of Central Africa, his habits are more arboreal than those of the gorilla; elsewhere, as on the south-west coast, he seems to live more upon the ground. His gait is weak and vacillating, and he can stand erect but a short time. These animals send forth loud cries; and the horrible wails, the furious shrieks and howls that may be heard morning and evening, and often in the night, make these creatures truly hateful to travellers. When chimpanzees are attacked, they strike the ground with their hands, but they do not, as the gorilla does, beat their breasts with their fists. As for the penthouses which Du Chaillu asserts these animals build, Professor Hartmann is somewhat doubtful regarding them. An illustration of this structure, as given by Du Chaillu, has been imitated in London, but this, in Hartmann’s opinion, has been embellished. ‘Koppenfels believes that the so-called penthouse is only the family nest, under which the male places himself; while Reichenfels thinks it possible that some parasitic growth, perhaps a _Loranthus_, gave rise to the belief that such a penthouse is erected.’ A male chimpanzee, which was kept in the Berlin Aquarium in 1876, was remarkable for his excessive liveliness, and was on particularly friendly terms with a little two-year-old boy, the son of Dr Hermes, the director of the aquarium. ‘When the child entered the room, the chimpanzee ran to meet him, embraced and kissed him, seized his hand and drew him to the sofa, that they might play together. The child was often rough with his playfellow, pulling him by the mouth, pinching his ears, or lying on him, yet the chimpanzee was never known to lose his temper. He behaved very differently to boys between six and ten years old. When a number of schoolboys visited the office, he ran towards them, went from one to the other, shook one of them, bit the leg of another, seized the jacket of a third with the right hand, jumped up, and with the left gave him a sound box on the ear. In short, he played the wildest pranks. It seemed as if he were infected with the joyous excitement of youth, which induced him to riot with the troop of schoolboys.’