582 



PHYSIOLOGY OF THE DOMESTIC ANIMALS. 



minute ; during rumination it varies from twenty-four to thirty -six, the 

 position appearing to be without influence. In bulls and oxen the rate 

 of respiration averages twenty in the minute. The frequent eructation 

 of gas and pauses caused by rumination render the rhythm of respiration 

 more irregular in ruminant than in other mammals. 



In the horse the normal respiratory movements ma} r be placed at 

 about ten in a minute ; after only the slight exercise of walking two 

 hundred yards, respiration in the horse may be increased to twenty -eight 



FIG. 254. GRAPHIC REPRESENTATION OF THE RESPIRATORY MOVEMENTS OF 

 A HORSE WHILE AT REST AND AFTER MOVEMENT. (Thanhoffer.) 



1, standing at rest ; 3, after a few minutes' walk : 7-8. after trotting ; 9, after a short rest : 11. after 

 several minutes' trotting and running ; 17, after a short rest from the trot and run ; 51, curve at the end of 

 the experiment. I = inspiration ; E = expiration ; i = time in seconds. 



in the minute, while after trotting five minutes the respirations were 

 found by Colin to be fifty-two to the minute, falling to forty in the fol- 

 lowing three minutes, and were fifty-two, likewise, in a minute after five 

 minutes' gallop (Fig. 254). 



In all animals similar facts may be noticed. Thus, in the sheep the 

 normal rate of respiration is fifteen in the minute, and after running may 

 be raised to one hundred or one hundred and forty in the minute ; or 



