Although they were written so long ago, the lectures on "Man's Place in Nature" are still the best existing treatise on the subject, and we shall give an outline of them, mentioning the chief points in which further work has been done. Information concerning the man-like apes was scattered in very different places, in the grave records of scientific societies, in the letters of travellers and missionaries, in the reports of the zoölogical societies which had been in possession of living specimens. The facts had to be sifted out from a great mass of verbiage and unfounded statement. With a characteristic desire for historical accuracy, more usual in a man of letters than in an anatomist, Huxley began with a study of classical and mediæval legends of the existence of pigmies and man-like creatures; but, while recognising that legends of satyrs and fauns were presages of the discovery of man-like apes, he was unable to find any actual record earlier than that contained in Pigafetta's _Description of the Kingdom of Congo_, drawn up from the notes of a Portuguese sailor and published in 1598. The descriptions and figures in this work apparently referred to chimpanzees. From this date onwards he traces the literature of the animals in question, and then proceeds to give an account of them. There are four distinct kinds of man-like apes: in Eastern Asia the Orangs and the Gibbons (although some later writers differ from Huxley in removing the Gibbons from the group of anthropoids); in Western Africa, the Chimpanzees and the Gorillas. All these have certain characters in common. They are inhabitants of the old world; they all have the same number of teeth as man, possessing four incisors, two canines, four premolars, and six true molars in each jaw, in the adult condition, while the milk dentition, as in man, consists of twenty teeth,--four incisors, two canines, and four molars in each jaw. Since Huxley wrote, a large bulk of additional work upon teeth has been published, and we now know that man and the anthropoid apes display the same kind of degenerative specialisation in their jaws. Simpler and older forms of mammals had a much larger number of teeth, and these differed among themselves more than the teeth of the higher forms. In the Anthropoids and Man, the jaws are proportionately shorter and less heavy than in simpler forms, and, in correspondence with this, the number of the teeth has become reduced, while the teeth themselves tend to form a more even row. The canine or eye-teeth are relatively smaller in the gorilla than in primitive mammals; they are still smaller in the lower races of man; while in ordinary civilised man they do not project above the others. The shortening of the jaw is still proceeding, and, although in lower races of man the last molar or wisdom tooth is almost as large as the molars in front of it, in the higher races the wisdom tooth is much smaller and frequently does