The Digestive System 



161 



the anterior region of the tongue during feeding is 

 covered with a layer of rather loose, scaly cells, 

 in most of which the nuclei may be seen. No 

 difference in the 

 amount of slough- 

 ing off can be no- 

 ticed as is the case 

 with the epithe- 

 lium of the roof of 

 the mouth. 



Figure 37 rep- 

 resents a section, 

 under very low 

 magnification, of 

 the covering of the 

 base of the tongue. 

 The areolar tissue, 

 a , is about the same 

 as in the preceding 

 section, except that it is more compact just under 

 the epithelium than it is in its deeper regions. 

 It seems also more vascular than in the preceding 

 section. 



The epithelium, e, is of the stratified squamous va- 

 riety, but consists of many more layers of cells than 

 in the preceding section and is hence several times 

 as thick. While its cells are flattened towards 

 the surface, after the manner of this kind of epithe- 

 lium, they do not form the definite horny layer de- 

 scribed above. 



FIG. 37. Covering of the posterior re- 

 gion of the tongue of the hibernating ani- 

 mal showing glands, under low magnifica- 

 tion; a, areolar tissue; bv, blood-vessels; 

 g, glands; e, epithelium. 



ii 



