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ause all these forms agree in certain structural respects that place them apart from the other mammalia, in the same way, for example, that the races of white men may be recognized as a group distinct from the black and red races. But comparative studies, prosecuted not only by those who have been forced to adopt the evolutionary interpretation, but also by believers in special creation like Linnaeus and Cuvier and other more modern opponents of evolution, have shown that the peculiar qualities of this order are shared by the human species. Indeed, the name of primates was given to this section by Linnaeus himself, because the human body found a place in the array which begins at the lower extreme with the lemurs and the monkeys and ends with man at the other end. Again it is found that no separate order of mammals exists to include only the genus _Homo_. To one unacquainted with the facts of vertebrate comparative anatomy, the distinguishing characteristics of the primates seem to be trivial in nature. It is surprising to find how insignificant are the details to which appeal must be made in order to draw a line between our own division of mammalia and the others. It is well to review them as they are given in the standard text-books of comparative anatomy. Primates are eutheria, or true mammalia possessing a placental attachment of the young within the parent. The first digits, namely, the "great toe" and the "thumb," are freely movable and opposable to the others, so that the limbs are prehensile and clasping structures; usually but not always the animals of this order are tree-dwellers in correlation with the grasping powers of the feet and hands. The permanent teeth succeed a shorter series of so-called "milk teeth," and they are diverse in structure, being incisors, canines, or "eye teeth," premolars, and molars; the particular numbers of each kind are almost invariable throughout the order and markedly different from those of other orders. The number of digits is always five, and with few exceptions they bear nails instead of claws. The clavicles, or "collar bones," are well developed in correlation with the prehensile nature of the fore limbs; a bony ring surrounds the orbit or eye socket. Finally there are two mammary glands by which the young are suckled. It is because any other details of difference between man and other forms are far less marked than the agreements in these respects, that the human species m
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