ROBERT RUSSELL BENSLEY 9 



described. This duct penetrates to the center of the lobule giving off radial tubular 

 branches which subdivide repeatedly until an exceedingly complex structure is pro- 

 duced. All tubules below the main duct give off at frequent intervals short tubules 

 which are regarded by Maziarski (1902) as acini. The cells lining all these branches 

 of the main duct, and indeed those of a large portion of the duct itself, are of precisely 

 the same character. 



The tubules are surrounded and supported by the collagenic connective tissue of 

 the tela submucosa, in which may be seen near the epithelium of the defect small 

 strands of smooth muscle fiber which represent the remains of the lamina muscularis 

 mucosse. In the tissue between the glands numerous mast cells may be seen, some 

 lying free in the connective tissue, others closely applied to the outer surface of the 

 glandular epithelial cells. 



The defect of the tunica mucosa, into which the ducts of the glands open, is cov- 

 ered by a single layer of epithelial cells. At the edge of the patch these consist of the 

 usual epithelial elements of the intestine, namely goblet cells, cylindrical epithelial 

 cells with basal cuticula, and granule cells of Paneth. Epithelium of this character, 

 however, extends over a very small portion of the extreme margin of the patch and is 

 broken by only a few ducts. The greater portion of the area is covered by cylindrical 

 epithelial cells of the mucigenous type. The shape and dimensions of these surface 

 epithelial cells vary within wide limits, according to the tension and shape, that is, 

 convexity or concavity, of the surface upon which they rest. On relaxed portions of 

 the surface, they are very high and narrow, 17-27 /* in height by 5-7 /* in width. If, 

 however, the tissue is fixed under tension, they appear short and wide and the position 

 and shape of the nucleus are similarly modified. 



At first sight the resemblance of the epithelium to that of the stomach is remark- 

 able, but on close examination it is foiind that this resemblance does not amount to 

 identity, although the differences are not of great importance. As in the gastric epi- 

 thelium, the distal portion of the cell is occupied by a mass of secretion forming a dis- 

 tinct theca. The proximal portion of the cell is occupied by finely reticular cytoplasm 

 and contains an oval nucleus. The latter may be slightly flattened where it comes into 

 contact with the mass of secretion. The differences between these cells and those of 

 the gastric epithelium are particularly emphasized in specimens stained in iron alum 

 hffimatoxylin, in muchsematin, or in mucicarmine. In the former stain the theca of the 

 gastric epithelial cell appears of a slightly grayish color and homogeneous. The 

 masses of mucin (granules?) which fill the theca are so closely aggregated that there is 

 but little cytoplasm left in the free ends of the cell to retain the stain. At the base of 

 the theca only, can be made out a delicate network, which extends from the cytoplasm 

 between the theca and the nucleus for a short distance into the mass of secretion. In 

 the epithelial cells of the Bruunerian area, on the other hand, the theca is subdivided 

 by delicate strands of cytoplasm forming a network in the meshes of which the 

 granules of mucin are lodged. Moreover, the theca is subdivided into proximal and 



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