BONES 



37 



In the pig there is an additional single bone — the os rostri, or 

 snout bone. 



56. The Trunk is also divided into spine, thorax, and pelvis. 



Bones of the Trunk. 



Horse. Ox. Dog. Pig. 



57. The Sternum, or breast-bone, is in seven sections, and in the 

 horse is placed edgeway up, while that of the cow lies flat. 



58. The Sacrum in the horse, ox, and sheep is composed of five 

 segments each ; in the dog, three ; and in the pig, four. The tail- 

 bones are variable in different animals. 



59. The Ribs of the ox are straighter, broader, and more uniform 

 than those of the horse ; they expand at their lower end, and the 

 true ribs (excepting the first) articulate with their cartilages by true 

 joints. The ox has also a small bone (sometimes two) in the heart, 

 and the dog has one in the penis. 



Bones of the Extremities. 

 60. Bones of the Fore-Legs (Right and Left) — 



