OF THE HEAD. 153 



short in comparison with those of most animals : for the 

 length of the lower maxillary bone of man, measured from 

 the chin to the posterior edge of the condyle, is only half the 

 length of the whole head, as taken from the chin to the 

 occiput ; and scarcely the ninth part of the height of the 

 body from the anus to the vertex ; and about the eighteenth 

 part of the whole length of the body from the top of the 

 head to the feet. This latter point of comparison is, how- 

 ever, scarcely applicable to the subject ; inasmuch as there 

 is hardly any animal, but man, which has the hind legs as 

 long as the trunk, neck and head taken together, and mea- 

 sured from the vertex to the pubes. 



The horizontal plane of the foramen magnum, its nearly 

 central position in the basis of the skull, the support of the 

 head by the spine, and the direction of tlie face forwards, 

 are admirably suited to the erect attitude of man, and 

 correspond to the absence of the ligamentum nuchee. If the 

 human spine were placed horizontally, how could the weight 

 of the head be sustained ? There is no adequate muscular 

 power to support and elevate the heavy mass ; not to men- 

 tion that it could not be carried sufficiently backwards on 

 the spine, for the eyes to be directed forwards ; and that, if 

 lowered, the jaws would not come to the ground, as they do 

 in animals, in consequence of their shortness, but the fore- 

 head or vertex would touch it *. 



In most animals, the great occipital foramen is placed at 

 the back of the head ; the jaws are considerably elongated ; 

 the occiput forms no projection beyond this opening, the 

 plane of which is vertical, or at least very slightly inclined. 

 Hence, the head is connected to the neck by its back part, 

 instead of being articulated, as in man, by the middle of its 

 basis ; and, instead of being in equilibrium on a perpendi- 

 cular column placed under it, it hangs to the front of the 

 neck, where its weight is sustained by the powerful cervical 



♦ The absence of the rete mirabile, and of all analogous provision for mo- 

 derating the influx of the blood into the brain, accords, with the other circum- 

 stances enumerated above, in shewing that man is entirely unfit for the atti- 

 tude on all-fours. 



