NERVE ENDINGS IN EPITHELIUM 



161 



Supporting ceil. 



Neuro-epit helial 

 cell. 



-Rod cell. 



upon the basement membrane, their narrower apex extends nearly to 

 the surface of the epithelium. The apex of the bud is thus covered by 

 the superficial squamous epithelial cells except for a narrow tubular 

 opening which overlies the superficial pole of the end organ. This 

 canal presents an external and an internal ostium, respectively desig- 

 nated the outer and inner taste pore. The inner taste pore leads into a 

 goblet-shaped depression in the apex of the taste bud, into which the 

 cuticular processes of the gustatory cells project. Composite buds with 

 two and three pores are g ^. 



common in the foliate 

 papilla of the rabbit; 

 Heidenhain (Anat. 



Anz., 45, 16, 1914) re- 

 ports also buds with 

 four, five and six pores. 



The taste buds con- 

 sist essentially of two 

 varieties of cells, the 

 gustatory and the sus- 

 tentacular. The latter 

 include the broad outer 

 sustentacular or teg- 

 mental cells at the sur- 

 face of the bud, the in- 

 ner sustentacular cells 

 within, and the basal 

 cells which lie near the 

 basement membrane. 



The Gustatory Cells. The gustatory cells are slender neuro-epithe- 

 lial structures whose nucleus causes a fusiform enlargement near their 

 center or toward the basal end. Their cytoplasm is finely granular; 

 their nucleus stains deeply and is ovoid or rod-shaped. The distal end 

 of the cell carries a delicate, highly refractive cuticular process which 

 projects beyond the apices of the sustentacular cells and as far as the 

 inner taste pore. Their proximal end is often bifid, forked, or so flat- 

 tened as to form a footlike 'extremity which is connected with the basal 

 cells by fine processes. Sapid substances in solution enter the pore and 

 stimulate the taste cells through the hair processes. 



Sustentacular Cells. The outer and inner sustentacular cells are 

 elongated epithelioid cells, having an ovoid or spheroidal vesicular 



fibrils. 



FIG. 175. SCHEMATIC REPRESENTATION OP A TASTE 

 BUD. 



(After Hermann, from Bohm and von Davidoff .) 



