10 INTRODUCTION. 



mouth ; secondly, there is a particular apparatus, which 

 forms these pellets ; and, thirdly, this apparatus consists 

 of the two closed apertures (ouvertures fermees) of the 

 many-plies, and of the oesophagus. Thus, the first two 

 cavities, in contracting, push the aliments which they 

 contain between the edges of the gastro-duct ; and the 

 gastro-duct, contracting in its turn, draws together the 

 two openings of the many-plies and oesophagus ; and 

 these two openings, closed at this moment of their 

 action, seize a portion of the food, detach it, and form 

 it into a pellet. 



The chief utility of rumination, as applicable to all 

 the animals in which it takes place, and the final pur- 

 pose of this wonderfully-complicated function in the 

 animal economy, are still imperfectly known; what 

 has been already suggested on these points is quite un- 

 satisfactory. Perrault and others supposed that it con- 

 tributed to the security of those animals, which are at 

 once voracious and timid, by showing the necessity of 

 their remaining long employed in chewing in an open 

 pasture; but the Indian buffalo ruminates, although 

 it does not fly even from the lion ; and the wild goat 

 dwells in Alpine countries, which are inaccessible to 

 beasts of prey. 



Whatever may be our ignorance of the cause or the 

 object of rumination, it is certain that the nature of 

 the food has a considerable influence in increasing or 

 diminishing the necessity for the performance of that 

 function. Thus, dry food requires to be entirely sub- 

 jected to a second mastication, before it can pass into 



