OSSEOUS SYSTEM OF MAMMALIA, 



55 



reader has only to compare the statues of female beauty with those of 

 Hercules, and these, again, with an Apollo or Antinous. 



As we recede from the human subject, whose skull rests nearly 

 poised on the vertebral column, and in whom the plane of the foramen 

 magnum is nearly horizontal, or, rather, directed somewhat obliquely 

 upward towards the face, we find the plane of the foramen magnum 

 to alter materially in its direction, becoming more and more vertical, and 

 directed obliquely upward and backward. In many of the Ape tribe, 

 it is nearly horizontal, or, if oblique, its obliquity is in a contrary 

 direction to that of the plane in the human skull : in the Dog, Cat, &c., 

 its obliquity is still greater ; till, at length, in some animals, and among 

 them the Cetacea, it becomes completely vertical. The diversities ob- 

 servable in the plane of this foramen, the degree of which influences, as 

 will be perceived, the position of the head, with regard to the spine, 

 are aptly illustrated by Daubenton's occipital angle. This angle is 

 formed by the intersection of a line, a, b, drawn, in the direction of the 

 foramen, with another, c, d, drawn from its posterior edge to the lower 

 margin of the orbit. See the annexed sketches (fig. 37). 



Illustrations of the difference of degree in the occipital angle. 



The angle thus given amounts, in the Dog, A, to sixty-two degrees ; 

 in the Lemur, B, to forty -seven degrees ; in the Orang, c, to about 

 thirty-seven degrees; but in Man, D, to no more than three. (See 

 Daubenton, in Mem. A cad. Sc. Paris.) 



A consideration of the skull leads to that of the vertebral column ; 

 a pile of bones, articulated together, of no less interest than importance, 

 constructed, so as to give grace and flexibility to the body, and yet pre- 

 serve from injury the medulla spinalis, enclosed in a continuous canal : 

 its design is both unique and beautiful. The mode of union subsisting 

 between its separate bones is so contrived, that, while the column, as a 

 whole, possesses considerable freedom of motion, the individual mobility 

 of each is very limited : but, to understand the mechanism of the spine 



