lick it off, but I have myself seen this done by a captive animal. They sleep in a sitting position without building nests: like other anthropoids, they digest their food quickly. In the case of gibbons, as of anthropoids generally, the length of the period of gestation is still a matter of uncertainty. The young are of slow development, and are not fully mature before their fourteenth or fifteenth year. Neither is the duration of their lives accurately known, since observations made on captive specimens only lead to vague conclusions. If we observe the processes of osseous development in the skeletons of aged specimens of gorillas in order to make an approximate estimate, we may infer that the duration of the life of anthropoids, at any rate in their larger forms, hardly falls short of the average length of human life. But up to this time the question remains undecided. These creatures do not appear to be free from morbid conditions in the wild life which is in conformity with their nature. In addition to the injuries to the hide and skeleton which may often be observed, and which have been caused by the weapons of man, or by the teeth and claws of their own kind, there are often traces, especially on the skulls of chimpanzees, of the decay of teeth and maxillary necrosis, as well as of curvatures, excrescences, and united fractures of other parts of the bony structure. This brief description is enough to show that anthropoids in their free life develop an intelligence which sets them high above the other mammals. They do not, however, display the keenness of scent and quickness of sight which distinguish some animals of a lower order, such as canine beasts of prey and ruminants manifest in many different ways. The structure of their nests is rude in comparison with that of some other mammals--as, for example, of rodents. But we must not forget that several of the lower races of men, such as the degraded Bedja, the Obongo, the Fuegians, many aborigines of the Brazilian forests, and the Australian blacks, scarcely rise above the inartificial structure of an anthropoid’s nest in the construction of their huts. CHAPTER VI. LIFE IN CAPTIVITY.