

CHAP. XXV.] THE INTESTINAL GLANDS. 235 



In Asiatic cholera all these glands become greatly enlarged from 

 the accumulation of a large quantity of granular matter in the 

 vesicles. 



Brunner's glands exhibit a remarkable immunity from disease ; 

 and in this, as in other respects, they resemble the pancreas. 



In concluding the account of the anatomy of the intestinal tube, 

 the following summary of the special characters of each portion of 

 it will serve to indicate more clearly what we have alluded to 

 above, that the physiological anatomy of the mucous membrane 

 affords the best basis for its subdivision into portions, each of 

 which, no doubt, exercises its special function in the digestive 

 process : 



In the duodenum, the mucous membrane exhibits, 1. cells and 

 tubes like pyloric cells, gradually passing into straight Lieberkiihn's 

 tubes, which exist throughout the rest of the gut ; 2. villi, com- 

 mencing in the upper part by the elongation of the septa between 

 the cells, the villi becoming extremely numerous and crowded 

 together in the inferior two-thirds; 3. in the lowest third, a few 

 solitary glands ; 4. Brunner's glands very numerous in the upper 

 part, gradually diminishing in size and number below ; 5. valvulse 

 conniventes well developed in the inferior half. 



The orifice by which the biliary and pancreatic ducts open into 

 the intestine, is placed where Brunner's glands have either become 

 very few or have ceased. In most of the Carnivora which we have 

 examined, these ducts open below the region of Brunner's glands ; 

 the point at which they pour their contents into the bowels has 

 therefore no constant relation to the duodenum, if, as it is conve- 

 nient to do, we may make the presence of these glands the charac- 

 teristic mark of that portion of the intestine. 



In the jejunum, the mucous membrane is characterised by, 

 1. Lieberkiihn's follicles and villi well developed; 2. valvulae 

 conniventes larger and more complete than elsewhere; 3. solitary 

 glands. 



The ileum exhibits, 1. Lieberkiihn's follicles and villi well-deve- 

 loped down to the ileo-co3cal valve; 2. valvulse conniventes, which 

 gradually diminish towards the termination of the ileum and disap- 

 pear ; 3. solitary glands ; 4. aggregate glands, or Peyer's patches, 

 which are small at the upper part of the ileum, but greatly increase 

 in size at its lowest portion. 



may be found in a paper by Dr. Handfield Jones, " On the Intestinal Mucous 

 Membrane." Lond. Med. Gazette, 1848. 



R 2 



