STRUCTURE OF THE SMALL INTESTINES. 



179 



Briinner's glands form, in some animals, a dense layer in the 

 submucous tissue of the beginning of the duodenum ; they are 

 small branched saccular -glands resembling mucous glands in 

 structure. Owing to their small size the secretion cannot be ob- 

 tained in sufficient quantity to make satisfactory experiments in 



FIG. 78. 



Section of the Mucous Membrane of small intestine, showing Lieber- 

 kiihn's follicles (a) with their irregular epithelium and the villi (6) passing 

 out of view ; (c) Muscularis mucosse; (d) Submucous tissue. (Cadiat.) 



respect to its properties. It is said to dissolve albumin and to 

 have a diastatic fermentative action, so that probably the secre- 

 tion is analogous to that of the pancreas, as Briinner originally 

 supposed. The quantity of fluid secreted by these glands is so 

 small that its existence is not taken into account in speaking of 



