48 



PBINCIPLES OF FEEDING FARM ANIMALS 



times before passing on to the large intestine. Each villus 

 (singular of villi) contains a lacteal of the lymphatic system, 

 surrounded by a net work of fine blood capillaries. Figure 

 10 shows the structure of a villus much enlarged. The 



^\ MUSCUIAR 

 " COAT 



Fig. 9. — Cross section of mucous nienibrane of .small iutestiuc, showing 

 capillaries and lacteals. (Jordan, Principles of Human Nutrition.) 



products of the digestion of the proteins, i.e. amino acids, 

 and of the starches and sugars, i.e. glucose and other simple 

 sugars, pass into the capillaries, through the portal vein 

 to the Hver, and into the general circulation of the blood. 

 The products of the digestion of crude fiber, v.e. salts of 

 acetic and butyric acids, also are probably absorbed into the 

 capillaries. In passing through the walls of the villi, the 



