THE INTESTINAL FLUID. 



201 



mass, with a strong alkaline reaction. (Frerichs.) Of course there 

 must be more or less true mucus, in all cases, in combination with 

 the secretion of the follicles. The morphological elements found 

 in this fluid are conoidal epithelium-cells (these having secreted it), 

 nuclei from the same probably, granular cells, and here and there a 

 little fat. 



This fluid averages 3.2 per cent, of solid constituents, .195 per 

 cent, being fat. 



The quantity of the intestinal fluid cannot be accurately ascer- 

 tained. Bidder and Schmidt calculate that about 9J ounces are 

 secreted in twenty -four hours by a man weighing 140 pounds. It 

 is secreted in greatest abundance four or five hours after a meal, 

 and is increased by drinks. 



Origin. The intestinal fluid is secreted by the epithelial cells of 

 the follicles of the small and of the large intestine. (Fig. 112.) 



Fig. 112. 



Follicles of small intestine, in their rela- 

 tions to the villi, showing their epithelium 

 (partly diagrammatic). F, F. Two follicles of 

 Lieberkuhn. b. Basement membrane, c. Sub- 

 mncous tissue, e. Conoidal epithelium, v. 

 Plane of the vessels. V. Villus with, and V 

 villas without epithelium, n. Nerve. 





Uses. This fluid is proved, by the experiments of Bidder and 

 Schmidt, to unite in itself the powers of both the gastric and the 

 pancreatic fluids i. e. it at the same time digests flesh and all albu- 

 minous substances, and also changes starch and prepares it for 

 absorption. It has been seen that the gastric fluid loses its power 

 as a digestive agent on arriving in the duodenum ; and the pan- 



