292 HANDBOOK OF PHYSIOLOGY. 



probably, from the difficulty with which they diffuse, absorbed, if at all, 

 almost solely by the lymphatics. 



(3.) The starchy, or amyloid portions of the food, the conversion of 

 which into dextrin and sugar was more or less interrupted during its 

 stay in the stomach, is now acted on briskly by the pancreatic juice and 

 the succus entericus; and the sugar as it is formed, is dissolved in the 

 intestinal fluids, and is absorbed chiefly by the blood-vessels. 



(4.) Saline and saccharine matters, as common salt, or cane sugar, 

 if not in a state of solution beforehand in the saliva or other fluids which 

 may have been swallowed with them, are at once dissolved in the 

 stomach, and if not here absorbed, are soon taken up in the small intes- 

 tine; the blood-vessels, as in the last case, being chiefly concerned in the 

 absorption. Cane sugar is in part or wholly converted into grape-sugar 

 before its absorption. This is accomplished partially in the stomach, 

 but also by a ferment in the succus entericus. 



(5.) The liquids, including in this term the ordinary drinks, as water, 

 wine, ale, tea, etc., which may have escaped absorption in the stomach, 

 are absorbed probably very soon after their entrance into the intestine; 

 the fluidity of the contents of the latter being preserved more by the 

 constant secretion of fluid by the intestinal glands, pancreas, and liver, 

 than by any given portion of fluid, whether swallowed or secreted, re- 

 maining long unabsorbed. From this fact, therefore, it may be gathered 

 that there is a kind of circulation constantly proceeding from the intes- 

 tines into the blood, and from the blood into the intestines again; for as 

 all the fluid a very large amount secreted by the intestinal glands, 

 must come from the blood, the latter would be too much drained, were 

 it not that the same fluid after secretion is again re-absorbed into the 

 current of blood going into the blood charged with nutrient products 

 of digestion coming out again by secretion through the glands in a 

 comparatively uncharged condition. 



At the lower end of the small intestine, the chyme, still thin and 

 pultaceous, is of a light yellow color, and has a distinctly fascal odor. 

 This odpr depends upon the formation of indol and its allies. In 

 this state it passes through the ileo-caacal opening into the large in- 

 testine. 



Summary of the Digestive Changes in the Large 

 Intestine. 



The changes which take place in the chyme in the large intestine are 

 probably only the continuation of the same changes that occur in the 

 course of the food's passage through the upper part of the intestinal canal. 

 From the absence of villi, however, we may conclude that absorption, 

 especially of fatty matter, is in great part completed in the small intes- 

 tine; while, from the still half-liquid, pultaceous consistence of the 



