OBSERVATIONS ON STRUCTURE OF CELLS AND NUCLEI. 14l 



secreting glands of the same animal, except, perhaps, that the 

 cells in the former are shorter than in the latter. But the cells 

 are mucous cells, as usually described, of the resting gland, i. e. 

 transparent cells containing " mucus ^' (see below). The outer 

 part of each cell is more or less drawn out and imbricated on 

 the membrana propria, and containing in its extremity the 

 somewhat compressed nucleus ; that is to say, the cell resembles 

 a goblet cell. The free border of the cell is open; this can only 

 be ascertained in a part of the section that does not exceed the 

 thickness of one cell ; in those parts that are two or three layers 

 deep the cells appear covered by a membrane of the same thick- 

 ness and refractive power as the substance that separates the 

 adjoining cells. The reason is obvious, viz. we see, de facto, the 

 substance separating the cells of two layers. I must therefore 

 differ in this respect from the assertions generally given to the 

 effect that most cells are closed towards the lumen. The sub- 

 stance of each cell shows two parts : (a), an inner half, trans- 

 parent and finely striated, owing to the jyre^^^wc^' of longitu- 

 dinal fibrils, which extend to the free border ; for this reason 

 the membrane that in thicker parts of the section appears 

 to cover this inner border seems in a certain focus to be 

 uniformly dotted, owing, no doubt, to it being seen either 

 above or below those fibrils; these fibrils anastomose only by 

 few lateral branchlets. {b) An outer half which contains a uni- 

 form network of fibrils ; it is, no doubt, this part of which Lav- 

 dowsky (see above) says that there are present in it '' traces " of 

 protoplasm in the shape of network. There are not only ''traces" 

 but a loell-developed networh of fibrils, and I am rather astonished 

 that Lavdowsky has not seen and figured it more clearlv, for the 

 appearances are very conspicuous. As in the case of the epi- 

 thelium of the intestines the nodes of this network appear 

 like dots, and with only a moderatelv Gjood lens one might 

 easily mistake this part for •'' granular.''' The fibrils of the inner 

 part are distinctly connected with the network of the outer part. 

 The distinction into these two parts can be made out when we 

 have a clear profile view of the cells, in an obHque or horizontal 

 view we do not, of course, perceive this distinction. When the 

 cells are viewed as a mosaic, i. e. in bird's-eye view, the sub- 

 stance of each polygonal figure appears to be composed of a 

 uniform network, but this probably is only the network of the 

 outer cell portion just mentioned. 



The " crescents "" of Gianuzzi or " parietal cells" of Heidenhain, 

 appear well developed, and I do not find them in any way 

 different, as regards number and disposition, from what they are 

 described by Heidenhain, Lavdowsky, and others. Their sub- 

 stance IS a dense nettoorh of fibrils. There are lobules or 



VOL. XIX. NEW SER. K 



