PECULIARITIES OF THE HUMAN SKELETON. 39 



face being comparatively light, and, secondly, by changes in 

 the form of the cranium, connected with the large size of the 

 brain. These changes consist mainly in the base of the 

 skull in front of the foramen magnum, being shortened and 

 curved downwards, and in the roof being greatly elongated 

 and arched, so that the part of the occipital bone behind 

 the foramen magnum, which in a quadruped looks back- 

 wards, is turned downwards, and a large part of the brain is 

 thus made to lie further back than the condyles by which 

 the occipital bone articulates with the atlas. 



Fig. 18. LlG AMENTUM NlJCILE OF THE HORSE. 



The elongation of the face downwards may be mentioned 

 as a human peculiarity, as well as the want of projection 

 forwards. This elongation is partly in connection with the 

 development of spaces, in which the voice reverberates and 

 acquires resonance, but cannot be altogether accounted 

 for by that consideration. Rather, it is a physiognomical 

 peculiarity of man, like the presence of a chin, well developed 

 in the higher varieties of the race, but not in subservience 

 to any special function. 



In the skeleton of the upper limb there is no mechanism 

 altogether peculiar to man ; the completely developed 

 clavicle, freely moving shoulder joint, pronation and supin- 

 ation of the forearm, opposability of the thumb., and. Qom- 



