260 ELEMENTARY PHYSIOLOGY. [XXV. 



Prepare thin vertical sections and observe 



a. The section of the ridges with the interven- 

 ing fossae. 



b. In each ridge three papilliform processes of 

 the dermis, one median, two lateral. 



c. The horny epidermis, consisting of cells very 

 flattened, but still retaining their nuclei, 

 covering the ridges and lining the fossa3. 



d. The Malpighian layer of the epidermis under- 

 neath the horny layer. In the fossse both 

 layers of the epidermis are thinner and less 

 marked off from one another than on the 

 surface. 



e. On the outside of each lateral papilla, and 

 therefore lining each side of the fossa, the 

 flask-shaped taste-buds 1 . There are usually 

 four nearly in contact one above the other. 



f. Each bud is in contact by its deeper part 

 with the dermis of the papilla, and has a short 

 neck running to the free surface of the 

 epidermis of the fossa where its circular open, 

 mouth may often be seen. 



g. The epidermic cells are flattened around its 

 median portion, forming a nest for it. 



h. The bud itself, with 



a. The external cover-cells, curved and 

 flattened, with conspicuous oval nuclei. 



1 Taste-buds in fungiform papillaB may be seen in sections of the 

 tip of the tongue of the cat. 



