ASSIMILATION 



87 



cells, known as the mucous membrane. Between this layer and 

 the muscular coats of the tract is a region of loosely arranged 

 cells with interlacing fibers, which make up the submucous layer 



Fig. 49. — Schematic representation of blood and Ij^mph vessels of the digestive 



tract. 



A, blood and lymph vessels in relation to entire wall of tract. B, blood capillaries in a 

 single villus of the human intestine. C, lymph vessel from center of same, a, artery; 

 6.C., blood capillaries; I, lymphatic vessel; I.e., lymph capillaries; 'ui.l., muscular layers of 

 intestine; m.m., mucous membrane; mes, mesentery; s.m., submucosa; v, vein. 



or submucosa. It is in this region, separated from the digestive 

 cavity by the mucous membrane, that the delicate lymphatics and 

 the thin-walled capillaries that connect arteries and veins are 



