THE DIGESTION OF THE NUTRIENTS 



49 



soaps and glycerin formed in the digestion of the fats are 

 recombined, forming fats again, and hberating the alkali of 

 the soaps. The fats enter the lacteals instead of the 

 capillaries and are carried into the lymphatic system, passing 

 into the general circulation of the blood 

 through the thoracic duct, which is 

 located in the neck. Figure 11 shows 

 the distended lacteals during absorption 

 in case of the horse. The mineral matter 

 of the feed is probabl}^ absorbed from 

 the small intestine \vithout any pre- 

 vious digestion, other than simple solu- 

 tion in the digestive juices. 



During the comparatively long time 

 tliat the feed residues remain in the 

 large intestine there is a marked ab- 

 sorption of water. There is also an 

 absorption of some of the products of 

 digestion by the enzymes carried in 



from the small intestine and of some of ,.^^°- lo. — Longitu- 

 dinal section of a 

 the products of bacterial fermentation \allus, showing: a, 



and putrefaction. This takes place faVier^V, lact^e'ai" 

 through the capillaries in the walls of (Joidan, Piincipie.s of 



Human Nutrition.) 



the large mtestme. 



Concerning digestion, Mathews ^ makes the following 

 statement : ''In short, the main object of the whole process 

 of cUgestion appears to be to resolve the various food sub- 

 stances into those common building stones, amino acids, 

 monosaccharides {i.e. simple sugars, as glucose) and fatty 

 acids, which are the common basis of all proteins, carbohy- 



1 "Physiological Chemistry," p. 446. 



