506 



exclude the possibility that these cells secrete small quantities of 

 enzymes. All recent work tends to show the omnipresence of such 

 substances in cells. In the clear cells of the glands of Brunner, 

 however, they are not present in sufficient quantities to be demon- 

 strable by the microchemical and histological means at our disposal. 



The fact that the rabbit is unique among mammals in possessing 

 serous components in its glands of Brunner, should speedily lead to 

 the examination of the secretion of these glands for important digestive 

 ferments ? 



The other conclusions of Bogomoletz' paper call for little comment 

 as the author is evidently unaware of the important papers recently 

 published by Schaffer ('91), Hock ('99), Castellant ('98), Maziarski 

 ('01) and Peiser ('02), dealing with the microscopical anatomy of the 

 glands of Brunner. Maziarski and Peiser have shown by the re- 

 construction method of Boru that the glands of Brunner are tubulo- 

 alveolar glands. This is in accordance with my own observations. 

 With regard to the nature of the ducts of the glands of Brunner, 

 Bogomoletz' statement that they open exclusively by independent 

 ducts between the bases of the villi, and never into the glands of 

 Lieberkühn, is not borne out by the facts. The most primitive con- 

 dition observed by me occurs in the opossum where the ducts of a 

 lobule open together on small circumscribed areas which are devoid 

 of villi and of glands of Lieberkühn, and which are covered by 

 epithelium similar to that of the stomach. In Erinaceus and Felis 

 the ducts are as a rule independent of the glands of Lieberkühn. 

 In Lutreola we have at the beginning of the area independent ducts ; 

 in the middle of the area, some of the ducts open into glands of 

 Lieberkühn, others are independent; at the end of the area, the 

 glands of Lieberkühn may pass through the muscularis mucosae and 

 divide in the tela submucosa, retaining their epithelium of cylindrical 

 and goblet cells, before receiving the ducts of the glands of Brunner. 

 We have thus illustrated in this single animal all of the types of 

 duct between the two extremes. In man Renaut's observations that 

 the glands of Brunner open into the bottoms or sides of the glands 

 of Lieberkühn has been confirmed by Schaffer, Castellant and 

 the writer. 



Bibliography. 



Bensley, E. R., The Structure of the Mammalian Gastric Glands. Quart. 



J. Micr. Sc, London, N. S. Vol. 41, 1898, p. 361—389. 

 — , The Structure of the Glands of Brunner. The Decennial Publications, 



University of Chicago, Vol. 10, 1903, p. 279—326. 



