ROBERT RUSSELL BENSLEY 17 



instead of opening in groups on a special area of the mucous membrane from which 

 glands of Lieberkuhn and villi are absent, penetrate between the former, traverse the 

 whole thickness of the mucous membrane, and open independently, on the surface, between 

 the bases of the intestinal villi. The epithelium at the mouth of these ducts presents, as 

 Schiefferdeoker (1884) has pointed out, a quite remarkable resemblance to gastric 

 epithelium, the same differences, however, being recognizable, as have been already 

 described for the epithelium of the defects of the Brunnerian area of the opossum. 



The resemblance of the cells of the glands of Brunner of these animals to those of 

 the pyloric glands is a very close one so close, indeed, that one is justified in declar- 

 ing that they are identical. In the glands of Brunner of the cat the subdivision of the 

 secretion into two masses is very obvious ; in the dog, in the resting condition, the cell 

 is so filled with secretion that such a subdivision cannot be made out, but if the cells 

 be exhausted by stimulation with pilocarpine or by feeding, it is seen that new secre- 

 tion is deposited in the neighborhood of the nucleus and forms a proximal mass. The 

 essentially similar changes in the pyloric-gland cells under experimental conditions of 

 secretion have already been described by the writer (1898). The differences between 

 the pyloric and Brunner's glands of these animals consist in the greater size of the 

 constituent tubules, to a large extent due to the expansion of the lumen, and in the 

 absence of the granular cells of Stehr from the glands of Brunner. Another difference 

 which is particularly obvious in the cat is the greater variability of the cells of Brunner's 

 glands in respect to the amount of mucin they contain. 



In both of these animals the secretion stains readily with muchaematein and 

 mucicarmiiie, applied in the way described above. For the cat and dog, however, I 

 have obtained the most satisfactory stain by employing the eosin-aurantia-indulin mix- 

 ture of Ehrlich diluted with twenty times its volume of water. By this means the 

 secretion of the glands of Brunner and of the pyloric glands is stained intensely blue, 

 the rest of the tissue red or yellow. The indulin mixture discriminates between the 

 mucin of the glands of Brunner and that of the goblet cells and of the gastric epithe- 

 lium, and brings out exquisitely the transition in type of the epithelium in passing up 

 the ducts. 



In the raccoon, the glands of Brunner extend a distance of about 35 mm. into the 

 duodenum. They form an aggregate of a number of fairly distinct elliptical lobules 

 imbedded in a tela submucosa composed of unusually dense, close-textured, collagenic 

 fibrous tissue. The lobules are confined to the tela submucosa except for the short 

 distance (1.6mm.) at the beginning of the intestine where a few groups of Brunner's 

 glands (pyloric glands?) occur in the deeper layers of the mucosa among the some- 

 what dispersed fibers of the lamina muscularis mucosae. 



The lamina muscularis mucosse is continuous, but perforated here and there by 

 the ducts of the glands of Brunner. For some distance on each side of the sphincter 

 pylori it is composed of longitudinal fibers only, the circular inner layer making its 

 appearance toward the end of the glands of Brunner. From the outer surface of the 



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