538 THE NERVOUS SYSTEM. 



branch of the glossopharyngeal nerve ; the apex is narrow and 

 communicates with the cavity of the mouth by a small pore in the 

 superficial epithelium gustatory pore. 



" The cells which compose the taste-buds are of two kinds, 

 viz.: 1. The gustatory cells, which are delicate fusiform or bipolar 

 cells composed of the cell-body or nucleated enlargement, and of 

 two processes, one distal, the other proximal. The distal process 

 is nearly straight, and passes toward the apex of the taste-bud, 



Papilla filiformis. 



' . 



. ^ _ Tongue epithe- 

 lium. 





_ Connective-tissue 



papilla. 



' ' : t ; ' .' ' 



-/- ->'- --"- - - " Mucosa. 



f'-t .'>' .' , Basal epithelial 



- - - v layer. 



FIG. 315. From a cross-section of the human tongue, showing short, thread-like 

 papillae (filiform) ; x 140 (Bohm and Davidoff). 



where it terminates in a small, highly refracting cilium-like 

 appendage which projects into the bottom of the pore above 

 mentioned. The proximal process is more delicate than the 

 other, and is often branched and varicose. The nerve-fibers take 

 origin in ramifications among the gustatory cells (Retzius). 



"2. The sustentacular cells (Fig. 318). These are elongated 

 cells, mostly flattened, and pointed at their ends ; they lie between 

 the gustatory cells, which they thus appear to support, and iu 

 addition they form a sort of envelope or covering to the taste-bud. 



