E. THE SMALL INTESTINE, BY E. VERSON. 



569 



mass. The latter arrangement is remarkably well seen in the 

 rat, in which animal the above-mentioned distribution of the 

 muscular fibres between the gland vesicles can be easily demon- 

 strated. 



The crypts of Lieberkuhn form tubular depressions of the 

 mucous membrane, the blind extremities of which extend to 



Fig. 109. 



Fig. 109. Crypts and interfollicular connective tissue. From the intes- 

 tine of the Rabbit. K, crypt ; a a, epithelium ; d, adenoid tissue, from 

 which the cells have been removed by pencilling ; T, fibrous tissue on 

 the opposite side. 



the muscularis mucosse, and as they are arranged perpendicu- 

 larly to the surface, they furnish a measure of the thickness of 

 the mucous membrane itself. Their length varies from O34 to 

 0'5 of a millimeter, their diameter amounts to 0'06 O08 of a 



