Metazoa Rana. 



319 



We must now briefly touch on the terminations of the 

 special sensory nerves connected with the senses of touch, 

 taste, smell, hearing, and sight. First of all we may begin 

 with the general statement that the ultimate fibrillae of all 

 these nerves are in the long run in direct connection with 

 more or less modified epithelial cells. 



Touch. The organ of touch is the skin, and in it fine 

 nerve-fibres are abundantly distributed, and their ultimate 



FtG. 175. -ClRCUMVALLATE PAPILLA FROM THE TONGUE OF THE CAT. 



(Schafer.) 



a, M, transverse and longitudinal sections of nerves in the dermis ; 7>, lym- 

 " phatic in a papilla of the dermis, / ; , gustatory body, or taste-bulb. 



fibrillge lie in close relation to the epithelial cells which 

 form the outer layer of the skin, although in the frog no 

 special organs of touch have been discovered. 



Taste. The organ of taste, at least in the higher 

 animals, lies in the tongue, and more especially in its 

 posterior third, where there is a limited number of papillae 

 of very peculiar character. Each consists of a broad 

 columnar projection of dermis and epidermis, surrounded 



