98 COMPARATIVE OSTEOLOGY. 



OSSA METATARSI PARVA, 

 (Fig. 24. 2, 3.) 



These also present the same general form as the small meta- 

 carpal bones ; the external is the longest and largest, and has the 

 largest head, with two facets which articulate with the cuboid 

 bone ; the internal one has also three articular facets, two for the 

 small, and one for the middle cuneiform bones. The two lateral 

 facets on each head articulate with corresponding ones on the 

 large metatarsal bone. 



The remaining bones of the hind extremity — viz., the three 

 phalanges, with their three small accessory bones, so closely 

 resemble the corresponding bones of the fore extremity, that 

 it seems at first sight difficult to distinguish the one from the 

 other ; the chief differences being, that the first phalanx of the 

 hind extremity is longer, its proximal end larger, and its distal 

 end smaller, than in the fore extremity. The second phalanx is 

 longer, but not so broad transversely, and the third is more pointed, 

 or semi-elliptical, in front, and more concave on its under surface, 

 all these differences being more or less marked in degree. The 

 three sesamoid bones are almost identical. 



COMPARATIVE OSTEOLOGY. 



In this section of the subject we shall endeavour to point out where the skele- 

 tons of the domesticated animals, other than the horse, differ from the typical 

 skeleton of the latter in any important particular. The following descriptions 

 are therefore in all cases comparisons, where comparison is possible, between 

 the typical skeleton and the skeleton in question. 



EUMINANTIA. 



In this class we take the Ox as the animal which represents best, for our 

 purpose, the family Cavicornia or Bovidas. 



Axial Skeleton, 

 the skull. 

 In the cranium of the ox an important feature is the development of the 

 frontal bone, which extends from below the eyes to the back of the skull, 

 forming the entire forehead and crest, in the middle of which is the frontal 

 tuberosity, which is very large in hornless animals. Springing from the sides 

 of the crest are two processes, varying in size and curvature, but corresponding 



