HOW THE ANIMAL BODY IS FORMED I7 



column, while the pubic bones of either side unite 

 below to complete the arch. The three bones of 

 each side of the pelvis are present in all our 

 domestic animals, including the fowls. 



Legbones of Farm Animals. — There is one 

 formula for the bones of the fore and hind legs of 

 farm animals. The first segment is a single bone, 

 the humerus of the fore leg, femur of the hind leg. 

 In the next segment there are two bones, radius 

 and ulna in the fore leg, tibia and fibula in the hind 

 leg. In the dog, cat, and Belgian hare the radius 

 and ulna are both well developed and distinct. In 

 ungulates the humerus is short and stout, while 

 the ulna is complete in the pig, rudimentary and 

 behind the radius in ruminants and firmly united 

 with the radius in the horse. Similarly with the 

 hind leg the fibula is a complete bone in the pig, 

 while in the horse there is merely a rudiment of it, 

 attached to the tibia. 



Feet. — The mammalian skeleton has undergone 

 the greatest modification in the bones of the feet. 

 In the horse there are only six of the original ten 

 wrist or carpal bones, and, since there is but one 

 of the original five toes, the horse has also but one 

 metacarpal or cannon bone. Splint-like rudiments 

 of two other metacarpal bones are to be found at 

 the upper end of the cannon bone, or at the " knee " 

 joint. Below the cannon bone, and forming the 

 shaft of the foot, we have the small cannon bone, 

 coronary bone, and cofiin bone — the last being 

 within the hoof with the navicular bone behind it. 

 The stifle joint of the horse corresponds to the knee 

 of man. The " knee " of the horse's fore leg cor- 

 responds to the hock of the hind leg, both being at 

 the upper end of the cannon bone. The fetlock 

 joint is between the large and small cannon bones, 



