CHIEF SUB-DIVISIONS OF MAMMALIA. 59 



among herbivorous quadrupeds ; these are the most powerful weapons with 

 which Carnivorous animals are furnished, serving both for the first attack of 

 their prey, and for subsequently tearing it in pieces. It is evident that the 

 whole structure of the body must undergo modification, in conformity with the 

 nature of the food. The simple stomach and intestinal canal of the carnivo- 

 rous animal, adapted only to the digestion of aliment consisting of materials 

 similar to those of its body, would be totally useless to an animal prevented by 

 its general organization from obtaining any other than vegetable food ; and on 

 the other hand, the teeth and hoofs of the herbivorous quadruped would be of 

 little assistance to an animal whose instincts and general conformation adapted 

 it for the pursuit of animal prey. It will be presently seen that, in regard to 

 his organization, Man holds an intermediate place, between the purely herbi- 

 vorous and the purely carnivorous tribes ; being capable of subsisting exclu- 

 sively upon either kind of diet, but being obviously intended by nature to 

 employ both in combination. 



61. The classification of the Mammalia by Linnaeus, although not strictly 

 natural, affords us the readiest means of separating Man zoologically from all 

 other animals. He arranged under his order Primates, all the unguiculated 

 Mammalia, which have four incisor teeth and two canines in each jaw ; and 

 thus Man, with the Monkeys and the Bats, was distinguished from the 

 remainder of those Quadrupeds, which have separate fingers with distinct 

 nails or claws. This group is now sub-divided into three orders, correspond- 

 ing with the Linnaean genera, Homo, Simla and Vespertilio. The last of 

 these orders, named Cheiroptera, includes the Bat tribe, which is easily sepa- 

 rated from all others, by the peculiar conformation of the anterior extremities, 

 from which its name is derived. The second, termed Quadrumana, compre- 

 hends the Apes, Monkeys, and Baboons, which exhibit a regular series, the 

 highest approaching Man in general conformation, and the lowest having 

 much more of the general organization of the inferior carnivorous quadrupeds. 

 They are distinguished from other viviparous Mammalia, by possessing an 

 opposable thumb on all four extremities (whence they are termed four-handed), 

 a character which is only found elsewhere in the Opossums. Although 

 some of the higher members of this group are capable of maintaining the 

 erect position without difficulty for some time, even whilst walking, it is cer- 

 tainly not that which is natural to them. The posterior extremity, being 

 formed on the plan of a hand, for prehension rather than for direct support, 

 is destitute of the heel which is characteristic of Man : and although Apes can 

 climb trees with facility, they cannot plant the foot firmly on the ground, so 

 as to resist attempts to overthrow them ; since the foot rests rather upon the 

 outer side than upon its sole, and the narrowness of the pelvis is unfavourable 

 to an equilibrium. There are many points of striking resemblance to Man, 

 however, in the details of the conformation of the Gtuadrumana, especially 

 among the most elevated species ; the order being distinguished by the same 

 characters from most others. The structure of their alimentary canal differs 

 extremely little from his. The eyes are directed forwards, when the trunk is 

 erect ; and the orbit is completely separated from the temporal fossae, by a 

 bony partition. The mammae are situated on the thorax ; and the penis is 

 pendant. Their coitus, however, is reverse, as in the lower Mammalia. The 

 form of the brain in the higher species corresponds with that of Man, in this 

 remarkable character, that it is divided into three lobes, of which the pos- 

 terior is prolongea backwards so as to cover the cerebellum ; this is not the 

 case in the hio-hest of the other Mammalia. 



