DIGESTIVE SYSTEM. 177 



fossa, hence their name. The wall consists of strati- 

 fied squamous epithelium and the core of connective 

 tissue richly supplied with blood-vessels. From this 

 core secondary connective-tissue papillae indent the 

 under surface of the stratified epithelial wall. 



Taste Buds. These are nests of epithelial cells 

 that lie in the lateral walls of circumvallate and 



Fig. 128. Longitudinal section of a human circumvallate papilla 

 (Bohm and Davidoff). 



many fungiform papillae, and are closely associated 

 with the sense of taste. They resemble small acorns, 

 and are made up of columnar cells so arranged as to 

 form a central taste canal, which in turn opens by a 

 pore into the circumvallate fossa. Two kinds of 

 slender epithelial cells are present, (i) tegmental or 



