STRUCTURE AND FUNCTION 



pulsive effort of the hindquarters is met by the forehand in 

 such a manner as to maintain the equilibrium as the body is 

 advanced. 



Locomotion is accomplished by the supporting columns being 



Fig. 2. — Skeleton of the horse, showing the vertebral arch and the bone columns, one 

 pair of legs supporting, the alternate pair, partially flexed, in a stride. 1, bones of the head; 

 1', lower jaw; 2, cervical vertebrae; 3, dorsal vertebrae; 4, lumbar vertebrae, 5, sacral vertebrae 

 (sacrum); 6, coccygeal vertebrae; 7, ribs; 8, sternum (breast-bone); 9, pelvis; 9', ilium; 9", 

 ischium; 10, scapula (shoulder-blade); 11, humerus; 12, radius; 13, ulna; 14, carpus (knee); 

 15, large metacarpal bone (canon); 16, rudimentary metacarpal bones (splint-bones); 

 17, OS suffraginis (long pastern); 18, os coronae (short pastern); 19, os pedis (hoof-bone); 

 20, sesamoid bones; 21, femur; 22, patella (knee-pan, stifle); 23, tibia; 24. fibula; 25, tarsus, 

 or hock; 26, large metatarsal bone (canon); 27, rudimentary metatarsals (splint bones); 

 28, OS suffraginis (long pastern); 29, os corona; (short pastern); 30, os pedis (hoof-bone, 

 "coflBn-bone"); 31, sesamoid bones. 



broken, and the foot elevated, by the flexion of the joints, into a 

 position from which it is advanced b}^ the subsequent extension of 

 the joints. A single advance of one foot constitutes a stride, and 

 a series of strides, which involve in turn the four feet, brings the 

 entire structure to an advanced position (Fig. 2). Each alter- 



