OBSERVATIONS ON STRUCTURE OF CELLS AND NUCLEI 1^3 



be seen already under a lens small, well-defined, more trans- 

 parent quasi-gelatinous portions, which under the microscope 

 show the characters, not of resting gland, but of one that has 

 slightly secreted, and he also notices the enlargement of the 

 '^ crescents'^ or parietal cells. The mucous cells, according to 

 Lavdowsky, show no change in these parts, except that their 

 nucleus is slightly larger and more rounded. I do not find this 

 alteration in the nucleus. Had Lavdowsky used hsematoxylin 

 staining for these parts, he would not have failed to notice that 

 the mucous cells are altered also in another respect, inasmuch 

 as they contain mucin instead of mucigen, besides being some- 

 what larger. Carmine staining, which Lavdowsky chiefly used, 

 does not show this diff'erence in the contents of the mucous cells. 



In the salivary gland of a dog, killed twenty minutes after 

 partaking of food, most ducts contain mucus, and in most 

 lobules we find the cells filled with mucin. 



A comparison of a submaxillary gland, as described above, with 

 one taken from an animal (dog) killed one hour after feeding, 

 shows the following difi'erences : — Although there are a good many 

 parts where a diff'erence between the gland structure taken from 

 this animal and one that had been killed twenty- four hours after 

 the last meal cannot be detected, still there are other parts — sec- 

 tions of lobules, and even whole lobules, in which the mucous 

 cells are decidedly shorter. Their substance appears more uni- 

 formly pervaded by the minute intracellular network of fibrils, 

 whereas the parietal cells are somewhat more prominent, being 

 larger. The nucleus of the mucous cells does not present the same 

 appearance or position as in the other case, being less compressed, 

 more irregular, and not so close to the merabrana propria. 



Pfliiger first pointed out^ that in the intralobular ducts — the part 

 that he called " Speichelrohren" — the columnar epithelial cells 

 lining them are in their outer portion composed of minute longi- 

 tudinal rods, whereas the inner portion appears more or less 

 homogeneous or slightly granular ; the circular or slightly oval 

 nucleus lies about the point where the two parts are in contact. 



Like Pfliiger, I see that in some tubes the epithelial cells 

 show a very fine striation also in the inner part ; and on look- 

 ing at this with a high power I am able to make out that these 

 longitudinal fibrils form also a network, and hence the " granu- 

 lar" appearance of this part. Unlike the other observers, I 

 notice that the nucleus of these epithelial cells contains a uniform 

 network, generally including only the uniform dots, occasionally 

 though not frequently containing also a large particle, corre- 

 sponding to the nucleolus of some authors. Further, I notice 



^ ' Arcliiv f. mikrosk, Anat.,' Baud v, p. 193. 



