Types and Market Classes of Live Stock 



403 



and upon the short end of levers composing the animal frame. Acting 

 in this way, speed and distance are gained with a corresponding reduc- 

 tion in the magnitude of the force. Because muscles are able to act 

 only through very short distances, it is necessary for them to act upon 

 the short end of the levers in order that sufficiently rapid movement 

 may be gained. 



The muscular system obtains its maximum development in the 

 horse, and upon the excellence of this, beauty of conformation largely 

 depends. Especially is this latter true of the neck and hindquarters. 

 There are no muscles below the knees and hocks — only their tendinous 

 prolongations. The first muscle under the skin almost covers the 



Fig. 146. — Skeleton of the horse. This illustration shows the location of the 

 bones and the degree to which the skeleton and the muscle influence the form. 



entire body and is the one that enables the animal to shake flies or any 

 irritating foreign substance off its skin. 



Digestive system.— The tongue is small as compared with that of 

 the ox. The capacity of the stomach is small, holding between 3 and 

 4 gallons, while the stomach of the ox holds 30 to 40 gallons. But 

 the small size of the organ is compensated for by the large size and 

 capacity of the intestines which hold twice that of the ox. The large 

 intestine has a capacity of about 20 gallons, and the small one 12 

 gallons. The liver is large, as are also the kidneys. 



Respiratory system. — The respiratory organs are well developed, 

 and comprise the nasal cavities, the larynx, the trachea, the bronchial 



