THE ABSORPTION OF THE FOOD-STUFFS 



131 



general lymphatic system and opens one way, by which 

 food can pass from the seat of absorption to the veins in 

 the thorax, there to mingle with the blood. Between 

 the exposed cells of the villus and the lymphatic at its 



X 



. 



A 





Fig. 20. This is a conventionalized drawing to show the essen- 

 tials in the structure of a villus. The lining cells of the intestine are 

 shown as in section. Within is seen a tangle of capillaries, and at the 

 very core of the villus a lymphatic (L). The loose tissue, which in 

 reality exists inside the villus, has been ignored for the sake of sim- 

 plicity. 



core is interposed a net of capillaries carrying blood which 

 has come from the neighboring aorta, and which will 

 flow through the liver before it returns to the heart. It 

 may be said at once that, of the two possible routes for 

 absorption, the portal system is the more important. 



