CHARACTERISTICS OF MAN. 67 



maiiuler of those Quadrupeds which have separate fingers with distinct nails 

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

 with the Linnoean genera, Homo, Simla, and Vespertilio. The last of these 

 orders, named Cheiroptera, consists of the Bat tribe, which is easily separated 

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

 which its name is derived. The second, termed Quadrumana, comprehends 

 the Apes, Monkeys, and Baboons, which exhibit a regular series ; the highest 

 approaching Maa 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 cha- 

 racter which is only found elsewhere in the Opossums. Although some of 

 the higher members of this group are capable of maintaining the erect posi- 

 tion without difficulty for some time, even whilst walking, it is certainly 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, how- 

 ever, in the details of the conformation of the Quadrumana, especially among 

 the most elevated species ; the order being distinguished by the same charac- 

 ters from most others. The structure of their alimentary canal differs ex- 

 tremely 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 mammas are situated on the thorax ; and the penis is 

 pendent. The 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 poste- 

 rior is prolonged backwards so as to cover the cerebellum ; this is not the case 

 in the highest of the other Mammalia. 



12. Characteristics of Man. 



51. We shall now review, somewhat in detail, the distinctive characters 

 that separate Man from those animals which present the nearest approach to 

 him in general structure and aspect. These may be advantageously classified 

 according to their obvious purposes ; and the first series we shall notice con- 

 sists of those by which Man is peculiarly adapted to the erect attitude. On 

 examining his cranium we remark that the condyles, by which it is articulated 

 with the spinal column, are so placed that a perpendicular dropped from the 

 centre of gravity of the head would nearly fall between them, so as to be 

 within the base on which it rests. The foramen magnum is not placed in the 

 centre of the base of the skull, but just behind it; in order to compensate for 

 the greater specific gravity of the posterior part of the head, which is entirely 

 filled with solid matter, whilst the anterior part contains many cavities. There 

 is, indeed, a little over-compensation, which gives a slight preponderance to 

 the front of the head; so that it drops forwards and downwards when all the 

 muscles are relaxed. But the muscles which are attached to the back of the 

 head are far larger and more numerous than those in front of the condyles ; 

 so that they are evidently intended to counteract this disposition; and we 

 find, accordingly, that we can keep up the head for the whole day, with so 

 slight and involuntary an effort that no fatigue is produced by it. Moreover, 

 the surfaces of the condyles have a horizontal direction when the head is 



