The Cynocephali, although they are placed after the different genera already described in the scheme of classification, have some very singular structural resemblances with the higher Apes and with man, besides those which render them more like the quadrupeds, such as the flesh-eaters or Carnivora. Several of these will be noticed in describing some of the kinds of Baboons; but it may be stated here that the bend in the back observed in the Chimpanzee and other Apes, which resembles that of a very young child more than that of a man, does not exist in these Dog-headed Apes. Their bones bend in and the upper part of the back bends out, as in man, so that there is a more or less graceful double curve. This is evident when any Baboon places himself up against the wires of his cage to be scratched--a treat under all circumstances. Moreover, the Baboon has another human resemblance, which is also observable in the Orangs, but not in the Troglodytes. In man, if a line be drawn down the spine and another drawn down the sacrum bone (that which unites the haunch-bones together behind), they will not meet and form a straight line, but will cut each other, so as to produce a decided angle. This is slightly seen in the Orangs, but it is very evident indeed in the Baboons. On the contrary, there is no angle formed in the Gorilla and Chimpanzee. Again, in man, the sacrum bone is curved, the hollow of the bend looking forwards. This is the case in the Baboon and also in the Siamang; but the curvature is much less in the great Apes or Troglodytes; furthermore, this sacrum bone is relatively very broad in the Baboon. Now, these are not simply anatomical curiosities, and they are really of some interest to the youngest naturalist who cares to try and puzzle out what these things really mean. Either they have a meaning or they have not. If they are freaks of Nature or the results of chance, then there is nothing more to be said; or if they are deeply connected with the method of life or the habits of the creatures, they may be said to have been given for a purpose. But the notions about chance and freaks belong to a bygone age, for Nature works neither by accident nor by impulses, but by law. So there must be some meaning in these things, and the key to their comprehension is the gradual change of form and of structure which has been undergone in the long ages during which one animal has become altered so as to depart greatly from the parent stock, and to assume what is called a new specific shape--to become a new kind. And in the new kind there are relics of the old form--pieces of bone here and there; muscles, tendons, or useless teeth, and such things, which are, as it were, part of the coat-of-arms to enable the genealogist to trace the history of the family.