ORGAN OF TASTE IN MAMMALIA. 



20.-J 



150 







151 



secondary papilla?, ib. A, in which the capillaries diverge and 

 divide to form their brush of loops, as in fig. 149, B, receiving 

 each its capillary loop, into the fasciculus of which the branch of 

 the artery a and vein v sub- 

 divides on entering: the 



O 



mushroom-like papilla or 

 process. 



The conical papillje clothe 

 as in a close-set pile the 

 anterior two-thirds of the 

 dorsum : they are longest 

 at the mid-line near the 

 centre of the tongue, small- 

 est near the sides and 

 at the tip. The cone-form, 

 with secondary papillae down 

 its sides,fig. 150, merges into 

 the cylindrical form, fig. 

 151, with a terminal brush of filaments. The excess of the scaly 

 covering of these, ib. a, b, c, forms the so-called ' fur ' of the 

 tongue, which becomes separated 

 from the deeper layer of epithe- 

 lium, d. In the conical variety, 

 fig. 150, a is the basal mem- 

 brane, b, c, the ' processes,' sub- 

 dividing into secondary or true 

 papillae, e, the deep layer of 

 epithelium, f, the superficial 

 layer, //, the points from which 

 the filamentary prolongations 

 would have projected : these 

 sometimes resemble fine hairs. 

 The function of such filiform 

 papilla? appears to be ' portative ' 

 and ( protective,' that of the coni- 

 cal papillae mainly ( tactile,' that 

 of the fungiform and fossulate 

 ones ( gustative : ' behind the 

 latter are the principal mucous 

 follicles. 



The so-called gustatory branch 

 of the fifth supplies the fungi- 

 form, conical, and filiform papillae ; the glossopharyngeal serves 



Filiform papilla. CCXL. 



