MAMMIFEROLS QUADRUPEDS. 48D 



columns of support to the trunk, which is placed 

 horizontally above them ; but the whole weight 

 of the body, together with that of the head and 

 neck, does not bear equally upon them ; the 

 fore extremities almost always sustain the greater 

 part of that weight, both because the fore part 

 of the trunk is itself heavier than the hind part, 

 and because it is loaded with the additional 

 weight of the head and neck. Hence, in the 

 usual attitude of standing, the pieces of which 

 the fore limbs are composed are required to be 

 placed more in a straight line than those of the 

 hinder limb : for the power of a column to sup- 

 port a weight is the greater in proportion as it 

 approaches to the perpendicular position. The 

 hind limbs are composed of exactly the same 

 number of divisions ; but the separate portions 

 are usually longer than those of the fore ex- 

 tremity, and consequently if they had been dis- 

 posed vertically in a straight line, they would 

 have elevated the hinder part of the trunk to too 

 great a height compared with the fore part. 

 This is obviated by their forming alternate 

 angles with one another. As the pelvis con- 

 nects the spine with the joint of the hip, and 

 even extends farther backwards, the thigh bone 

 must necessarily be brought forwards ; then the 

 tibia and fibula, which compose the bones of the 

 leg must be carried backwards to their junction 

 with the bones of the foot; and again the foot 



