SEC. 5. ABSORPTION OF THE PRODUCTS OF DIGESTION. 



We have seen that absorption does, or at least may, take place 

 from the stomach. We have also stated that a large absorption, 

 especially of water, occurs along the whole large intestine. We 

 may add that absorption from the large intestine after injection 

 per anum or through a fistula has been observed not only in the 

 case of soluble peptone and sugar, but also in that of starch, white 

 of egg, and casein, though the exact changes undergone by the 

 latter previous to absorption are as yet unknown. 



Nevertheless the largest and most important part of the digested 

 material passes away from the canal, during the transit of food 

 along the small intestine, partly into the lacteals, partly into the 

 portal vessels. The portal vessels are simply parts of the general 

 vascular system, but the lacteals, into which we may at once say 

 the greater part of the fat passes, need special attention. 



The Lymphatics. 



Characters of Chyle. In a fasting animal the contents of the 

 thoracic duct are clear and transparent ; shortly after a meal they 

 become milky and opaque, the change being entirely due to a 

 difference in the quality and quantity of the fluid brought to 

 the duct by the lacteals, that fluid also being, as seen by inspection 



