53 



fore it was killed, and the fat is being absorbed by the epithelial 

 cells ; the globules in the epithelium are blackened by the osmic 

 acid of the Flemming's fluid. If desired the preparation may be 

 stained with safranin (§§ 89, 99). 



The intestine of the frog has no villi, the elevations of the 

 mucosa shown in the transection are folds cut across. The epi- 

 thelial cells covering the villi in mammals, however, have the same 

 function in the absorption of fat (6). 



(91). Ileum. Cat. Re-examine this preparation in the light 

 of the knowledge gained of the structure of the intestine, noting 

 the lymph follicles and their relation to the intestinal epithelium ; 

 the occurrence of lymph cells in and upon the epithelium. Identify 

 also the coats and structures mentioned under 104, save, of course, 

 Brunner's glands, which are limited to the cephalic part of the 

 duodenum. 



