DIGESTION AND RESORPTION 



105 



3. RESORPTION THE FECES 



148. Definition. As was 'stated at the beginning of this 

 chapter (113), the digested feed contained in the alimentary 

 canal is really outside the body, just as in the case of the ameba. 

 In order to enter the body, the digested material must pass 

 through or be taken up by the cells surrounding the digestive 

 cavity. The process by which the products of the digestion of 

 the feed are transferred from the digestive organs to the circulat- 

 ing media (blood and lymph) of the body is called resorption. 



149. Epithelium. Villi. The inner, or mucous, membrane 

 of the digestive tract bears on its surface a layer of epi- 



FIG. 14. Section of villi. (Bohm, Davidorf, Huber, Text Book of Histology.) 



thelial cells, more or less resembling those lining the mouth, which 

 is closely underlaid with a network of blood capillaries and 

 lymph vessels. It is these epithelial cells which are the active 

 agents in resorption. 



