DIGESTIVE SYSTEM. 



179 



taste bud. It is evident that a food to be tasted 

 must first be put into solution to pass into the sulcus 

 and stimulate the delicate processes of the gustatory 

 cells of taste buds. 



Foliate Papillae. On each side of the rabbit's 

 tongue, some distance back, can be seen a small oval 

 patch, with diagonal grooves and ridges, resembling 

 the side of a three-cornered file. These patches are 

 the foliate papilla. In reality they are not papillae 

 but alternating grooves and ridges. In transverse 

 section, the lateral walls of the ridges will be found 

 beset with taste buds resembling in detail those 



Fig. 130. Section through 

 taste bud. 



CL 



Fig. 131. Cells from a taste 

 bud: a, taste cells; b, supporting 

 cells. 



described in the circumvallate papillae. The rabbit, 

 therefore, to relish his clover, should roll the leaves 

 over these lateral patches. 



Glands of the Tongue. Small serous racemose 

 glands are associated with the circumvallate pa- 

 pillae into the fossa of which their ducts open. 

 Glands are otherwise absent over the dorsum of the 

 tongue. Over the other parts of the tongue both 

 serous and mucous glands are abundantly present. 

 Many of these are mixed serous and mucous glands. 



