THE MOUTH AND TONGUE. 381 



form papillae the epithelium is of the horny variety, and its 

 arrangement is imbricated, the lower margin of each scale over- 

 lapping the upper border of the scale next below it. In the 

 axes of the filiform papillae large-sized arterial and venous 

 capillaries extend. Each secondary papilla contains a vascu- 

 lar loop. The papillae of smallest size contain a fine network 

 of vessels, and in the posterior part of the tongue simple capil- 

 lary loops. Neither the filiform papillae nor their secondary 

 papillae contain nerve-fibrils. The latter are found, however, 

 at the base of the papillae, where they end in rounded terminal 

 bulbs. 



The fungiform papillce are larger than the filiform, and 

 their epithelial covering is much thinner. They appear as 

 rounded prominences, somewhat constricted at the base, and 

 covered upon the sides and top with many cone-shaped second- 

 ary papillae. The free surface of some fungiform papillae is 

 smooth, the secondary papillae being farther apart. These are 

 found most commonly at the lateral edges of the tongue, and 

 are the so-called lenticular papillae. The distribution of the 

 fungiform papillae is rather irregular, and it varies in different 

 individuals. At the base of the tongue, and generally at its 

 lateral portions, between the filiform papillae, they are some- 

 times scarce and sometimes quite abundant. Toward the tip 

 of the tongue they are smaller, while they are larger in the 

 region of the circumvallate papillae. They are covered with 

 several layers of pavement-epithelium, the deeper strata of 

 which are formed by smaller polygonal prickle-cells. In this 

 epithelial covering, upon the surface of the fungiform papillae, 

 are constantly found peculiar bodies, called the " taste-goblets." 



The taste-goblets vary in size and shape in different ani- 

 mals, and also in the same animal, according to the locality 

 in which they are found. They usually resemble a short- 

 necked flask, their longest diameter being the longitudinal. 

 The lower part of the taste-goblet rests upon the submucosa ; 

 the body, and more especially the part which corresponds to 

 the neck of the flask, is surrounded by epithelial cells. Every 

 taste-goblet has at the surface of the epithelium an opening 

 called aporus, which word is frequently used not only to des- 

 ignate the exterior opening, but also for the entire short canal 

 in the epithelial layer. The diameter of the porus is from 

 .0064 to .0198 mm. It is surrounded by two and sometimes by 



