OF THE CLASS MAMMALIA. 



239 



392. Conformation of the Head. In the form of the 

 osseous head, the size of the cranial capacity, compared with 

 the area of the face, is supposed to be in the ratio of the in* 

 telligence, with certain exceptions ; as we recede from man, 

 the face becomes comparatively larger, and the cerebral cavity 

 smaller, proportionally to the face ; the orbits are directed 

 more outwards, and cease to be distinct from the temporal 

 fossae ; and the occipital condyles, which in man are found at 

 the base of the cranium, and which form the plane by which 

 the head rests on the vertebral column, recede more and more, 

 until they come to be placed almost on a line with the axis of 

 the body. The same happens with the jaws. Still, we find 



Fig. 197. Skeleton of the Camel. (See page 141 .) 



always the same bones, the same form of articulation of the 

 lower jaw ; between its condyles and the temporal bone there 

 is no intermediate bone, as in birds, reptiles, batrachia, and 

 fishes. 



393. Various mammals are provided with horns. These 



