DIGESTIVE ORGANS AND THEIR ANATOMY. 



283 



it to be covered with fine projections not entirely unlike the 

 "pile" on velvet. Examination with the microscope shows 



Fig. 112. PORTION OF THE SMALL INTESTINE TO SHOW THE VALVUL.E CONNIVENTES. 

 (Brinton.) 



that these little projections are finger-like protrusions of the 

 mucous membrane. These are called the ( 'villi, ' ' and are in 



Fig. 113. SECTION OF A HUMAN INTESTINAL MUCOUS MEMBRANE, SHOWING THREE COM- 

 PLETE VILLI AND six CRYPTS OF LJEBERKUHN. (After Bohm and v. Davidoff.) 



an integral way concerned in the absorption of the foods. 

 Between these villi and dipping down into the mucous mem- 



