LESSON 63.] 



NUTKITION IN MAN. 



217 



FIG. 342. 



hole (white in the preparation) shows where the glands of Peyer have 

 sloughed off. In phthisis these glands are liable to become the seat 

 of tubercular deposit, and also of an ulcerative process, whence re- 

 sults the diarrhoea, so troublesome in that disease. In Asiatic chol- 

 era they become greatly enlarged from the accumulation of granular 

 matter in the vesicles. 



Brunner's glands are remarkably free from tendency to disease. 



947. The mucous membrane of the large intestine in man, as in 

 other animals, bears a close resemblance 



to the like tissue of the stomach, but in 

 man (and the Monkey) again we find 

 that a delicate plexus of capillaries, not 

 single vessels, forms the boundaries of 

 the cells (Fig. 342). 



948. Solitary glands are abundantly 

 found in the large intestine ; they are of 

 large size, and exhibit a funnel-shaped 

 cavity (see Fig. 293) or pit-like aperture, 



which forms a depression of the mucous membrane ; at the bottom 

 of this follicle lies a closed, somewhat flattened gland, exactly the 

 same in structure, and possessing similar contents to the glands of 

 the small intestines. 



It has already been observed that the mucous membranes in the 

 Monkey are identical with similar structures in man, and two illus- 

 trations are offered in confirmation of this fact. 



The first (Fig. 343) is from the Jejunum, and exhibits villi of 



Human Colon. 



FIG. 343. 



FIG. 344. 



Jejunum, Monkey. Colon, Monkey. 



the same size and shape, and the same display of mucus-crypts, as 

 the corresponding human intestine. 



The second (Fig. 344) is from the Colon, and again the same 

 exact parallelism exists. While the cells of such tissue in all other 

 animals are surrounded by single vessels only, it is reserved for man 

 and the Monkey to display a plexus in the same situation. 



