RUMINATION. 141 



Ruminating animals require a considerable length of time 

 effectually to rechew their provender, and it is calculated by 

 Colin that the fourth of the day requires to be expended by 

 them in rumination. I may here refer to an important ob- 

 servation I have made, viz., that rapidly-grown grasses, such as 

 the crops grown on irrigated meadows, distend the rumen 

 far more in proportion to their solid elements than other food. 

 The distended paunch, however, soon diminishes in size, and 

 the animal then appears very empty, and cannot as effectually 

 ruminate such food as the harder and better kind. It must 

 not be forgotten, that a certain volume of food must exist in 

 the paunch, in order that rumination may go on, and if the 

 essential bulk of very soft grasses is readily reduced by a 

 speedy separation of the moisture, the act must be compara- 

 tively imperfect. This is a subject which merits investiga- 

 tion in connection with determining what foods most favour 

 the natural action of the stomachs in ruminants. 



The mastication of the regurgitated bolus is very complete, 

 and varies in accordance with the toughness or succulent 

 nature of the food. Many circumstances seem to affect the 

 extent to which food is chewed the second time, and Aris- 

 totle declared that animals ruminated more in winter than 

 summer. Brugnone said that green food required from 

 30 to 33 strokes of the teeth, and dry food 45 to 55, during 

 the second mastication. Young and very old animals chew 

 more than healthy adults. 



The act of chewing is either one-sided or alternate, and a 

 very strange fact has been noticed, that the first stroke of 

 the molars is in an opposite direction to the regular action 

 which follows it. Thus, if on the one side chewing, an ox is 

 masticating from right to left, the first stroke will be ob- 

 served from left to right. 



Colin confirms a statement made originally by Fluorens, 



