19 



metacarpus (cannon bone), occupying the space between the 

 splint bones; it passes down immediately behind the cannon 

 bone, lying between it and the tendon of the flexor pedis perfor- 

 ans, bifurcating (dividing into two) about the lower third of 

 this bone and becoming attached to the sesamoids, whence the 

 parts pass forward and downward, joining the tendon of the 

 extensor pedis just above the pastern joint. It is thin and com- 

 paratively weak toward the knee, but as it approaches the fetlock 

 joint it almost equals the back tendons (sinews) in substance, 

 and its volume and wiriness to the touch may be taken as some 

 test of the power of any particular leg to resist a breakdown. 



The suspensory ligament of the hind leg corresponds in every 

 particular with that of the fore leg. 



The calcaneo-cuboid ligament stretches from the posterior 

 border of the calcaneum to the posterior part of the cuboid, 

 ending on the head of the external splint bone. A sprain of this 

 ligament is known as a " curb."' 



MUSCLES AND TENDONS. 



The muscles are divided into voluntary and involuntary mus- 

 cles; the former being under the direct control of the will, as, 

 for example, the miiscles of the neck, legs, tail, etc.; and the lat- 

 ter acting in;l3p3n;l3iitly of the animal's will, as, for example, 

 the heart, intestines, etc. 



The muscles form about one-half of the entire weight of the 

 body. With regard to their form they are di^^ded into long, wide, 

 and short. Long muscles are generally found in the limbs; wide 

 muscles are stretched beneath the skin or around the great cav- 

 ities of the trunk, and the short muscles are found chiefly around 

 the short bones. 



Ten ions are white, round or flattened cords affixed to the 

 extremities of the long muscles. They stretch or contract the 

 muscles, but do not themselves change form. 



The wide muscles are provided with broad bands of fibrous 

 tissue, by means of which they are attached to other structures. 



Extensor muscles (extensors) have the power of extending one 

 bone upon another and the flexor muscles (flexors) have the 

 opposite action. 



The extensor pedis is the principal extensor of the fore leg; it 

 originates at the inferior extremity of the humerus, and its fleshy 



