276 



PHYSIOLOGY OF THE DOMESTIC ANIMALS. 



glands secrete alternately during mastication, both in the horse and 



ruminant animals, and, in all probability, also in the omnivora, the 



secretion occurring on the side 

 on which mastication is taking 

 place. Thus, when mastication 

 is takin P lace Between the right 

 molar teeth, then it is the right 

 parotid alone, in the horse, which 

 secretes, and it is the right 

 parotid in the ruminant which 

 has the highest activity. Ex- 

 IN THE HORSE, periments conducted by Colin, 

 by making a fistula of the parotid 

 ducts in the horse and the ass, 



have demonstrated the truth of these statements. The following tables 



represent some of his results : 



2, 



FIG. 114. PAROTID FISTULA 

 (Bernard.) 



a, duct of Steno, with cannula inserted, and rubber bag for 

 collecting the saliva. 



