44 JUDGING FARM ANIMALS 



of the abdominal cavity. It is the largest gland of the 

 body, weighing ten to twelve pounds, and extending from 

 within three or four inches of the floor of the abdominal 

 cavity, just above the elbow, to a level with the right kidney, 

 just below the loin. 



The heart of the horse, located down in the left side 

 of the chest, is a hollow muscle that under average condi- 

 tions weighs about nine pounds, but may vary greatly in 

 size. Dr. Sisson states 7 that, ' ' as might be expected, race 

 horses have hearts which are larger than the average, both 



Fig. 23. Viscera of mare : L, liver ; Ma, stomach, the posterior contour 

 being indicated by dotted line x ; Mi spleen ; IN, left kidney ; D, small in- 

 testine, partly removed ; IdC and IvC, large intestine ; H, bladder ; aa, bb', 

 heart ; M', rectum ; V, vagina. (Courtesy Dr. S. Sisson. From Anatomy 

 of the Domestic Animals.) 



absolutely and relatively." Small horses show more ac- 

 tivity of heart action than large ones, with more rapid 

 pulsation. 



The lungs of the horse occupy much of the upper chest 

 cavity, and average about seven and one-half pounds in 

 weight. The right lung weighs about half as much as the 

 left one. The size and capacity of the lungs are important. 

 Of two horses of equal size, the one having the larger lungs 



7 Anatomy of the Domestic Animals, 1914, p. 620. 



