68 



ON THE PLACE OF MAN IN THE SCALE OF BEING. 



upright ; and thus the weight of the skull is laid vertically by them upon the 

 top of the vertebral column. If these arrangements be compared with the 

 position and direction of the occipital condyles in other Mammalia, it will 

 be found that these are placed in the latter much nearer to the back of the 

 head, and that their plane is more oblique. Thus, whilst the foramen mag- 

 num is situated, in Man, just behind the centre of the base of the skull, it is 

 found in the Chimpanzee and Orang Outan to occupy the middle of the 

 posterior third ; and, as we descend through the scale of Mammalia, we ob- 

 serve that it gradually approaches the back of the skull, and at last comes 

 nearly into the line of its longest diameter, as we see in the Horse. The 

 obliquity of the condyles differs in a similar degree. In all Mammalia except 

 Man their plane is oblique; so that, even if the head were equally balanced 

 upon them, the force of gravity would tend to carry it forwards and down- 

 wards. In Man, the angle which they make with the horizontal is very 

 small ; in the Orang Outan it is as much as 37; and in the Horse their 

 plane is vertical, making the angle 90. If, therefore, the natural posture of 

 Man were horizontal, he would in this respect be circumstanced like the 

 Horse; for the plane of his condyles, which is nearly horizontal in the erect 

 position, would then be vertical : and the head, instead of being nearly 

 balanced in the erect position, would hang at the end of the neck, so that its 

 whole weight would have to be supported by some external and constantly- 

 acting power. But for this there is neither in the skeleton, nor in the muscu- 

 lar system of Man, any adequate provision. In other Mammalia the head is 

 maintained in such a position by a strong and thick ligament (the ligamentum 

 micha?), which passes from the spines of the cervical and dorsal vertebra? to 

 the most prominent part of the occiput; but of this there is scarcely any 



Fig. 5. 



View of the base of skull of Man, compared with that of the Orang Outan. 



trace in Man. In the horizontal position, therefore, he would have the heavi- 

 est head, with the least power of supporting it. 



52. The position of the face immediately beneath the brain, so that its 

 1'ront is nearly in the same plane as the forehead, is peculiarly characteristic 

 of Man ; for the crania of the Chimpanzee and Orang, which approach 

 nearest to that of Man, arc entirely posterior to, and not above, the face. It 

 should be remarked that in the young Ape there is a much greater resem- 

 blance to Man in this respect than there is in the adult. For at the time of 

 the second dentition the muzzle of the Ape undergoes a great elongation, so 



