Now if, by means of comparative anatomy and ontogeny, we seek for man’s position in that Natural System of animals which formed the subject of the last two chapters, the incontrovertible fact will at once present itself to us, that man belongs to the tribe, or phylum, of the Vertebrata. Every one of the characteristics, which so strikingly distinguish all the Vertebrata from all Invertebrata, is possessed by him. It has also never been doubted that of all the Vertebrata the Mammals are most closely allied to Man, and that he possesses all the characteristic features distinguishing them from all other Vertebrata. If then we further carefully examine the three different main groups or sub-classes of Mammals—the inter-connections of which were discussed in our last chapter—there cannot be the slightest doubt that Man belongs to the Placentals, and shares with all other Placentals, the important characteristics which distinguish them from Marsupials and from Cloacals. Finally, of the two main groups of placental Mammals, the Deciduata and the Indeciduata, the group of Deciduata doubtless includes Man. For the human embryo is developed with a genuine decidua, and is thus absolutely distinguished from all the Indeciduata. Among the Deciduata we distinguish two legions, the Zonoplacentalia, with girdle-shaped placenta (Beasts of Prey and Pseudo-hoofed animals), and the Discoplacentalia, with disc-shaped placenta (all the remaining Deciduata). Man possesses a disc-shaped placenta, like all Discoplacentalia; and thus our next question must be, What is man’s position in this group? In the last chapter we distinguished the following five orders of Discoplacentalia: (1) Semi-apes; (2) Rodents; (3) Insectivora; (4) Bats; (5) Apes. The last of these five orders, that of Apes, is, as every one knows, in every bodily feature far more closely allied to Man than the four others. Hence the only remaining question now is, whether, in the system of animals, Man is to be directly classed in the order of genuine Apes, or whether he is to be considered as the representative of a special sixth order of Discoplacentalia, allied to, but more advanced than, that of the Apes.