Loss of Muscle. 165 



the number and extent of contractions — which give rise to 

 all motion in animals — and the supply of blood to the mus- 

 cles while contracted, increase, ascording to the increase 

 in exercise by cattle, horses, or swine. 



In the marmot and other hibernating animals, the blood 

 heat is reduced nearly as low as the temperature of the sur- 

 rounding air, the rate of breathing being reduced from five 

 hundred to fourteen beats in an hour,* while the rate of 

 pulsation from the blood circulation is reduced from one 

 hundred and fifty to fifteen beats per minute, which shows 

 the effect of extremely reduced motion, or of almost total 

 inaction in the locomotive organs. The slight interior 

 motion, caused by the slow pulsation and breathing, com- 

 prising the sum of motion in the body of the marmot while 

 hibernating, strongly contrasts with the active exercise and 

 equally active breathing during exercise by cattle, or swine, 

 or horses. And in the increase in breathing and blood, 

 we have the source of increased nutrition and growth of 

 muscle. 



That the breathing of cattle is reduced some 40 per cent 

 by tying, or any close confinement, during the five or six 

 months of winter each year, is evident, and a reduction of 

 20 to 30 per cent in the blood and muscles of cattle so 

 closely restricted in their exercise, appears reasonably cer- 

 tain. This reduction of red blood and muscle, or flesh, 

 in store cattle of all ages, is very general, through the Mid- 

 dle and Northern States. The reduction of exercise cor- 

 respondingly reduces the extent of muscular contraction, 

 blood circulation, and nutrition, in the muscles; being 

 thereby reduced according to the reduced extent of exer- 

 cise. This is what happens to milk cows, in large num- 

 bers, that are closely confined ; also, to store cattle of all 

 kinds, that have their exercise reduced to the minimum 

 extent during the comparatively still condition through 



* Bead Youmans' Chemistry, p. 445. 



