OBSERVATIONS ON STRUCTURE OF CELLS AND NUCLEI. 1^7 



the network of both the parietal and chief cells very beautifully. 

 The chief cells contain in these specimens a network very simi- 

 lar to that described above of the mucous cells^ but the meshes 

 of the network are not quite as large in the former as in the 

 latter. Comparing the chief cells of the fundus of stomach of a 

 dog killed twenty-four hours after partaking of food (the 

 stomach being found empty), with the same cells of a dog, about 

 the same age, one hour after a copious meal of meat, it is seen that 

 in the latter instance they are larger (Heidenhain), and that they 

 show the network more distinct, being more open than in the former. 

 In figure 17 I have represented the appearances presented by 

 the chief cells and parietal cells of fundus of stomach of dog, 

 the stomach having been hardened in the above mixture of 

 chromic acid and spirit. As I mention in the explanation of 

 figure 12 to the plate vii, accompanying this paper, the struc- 

 tural appearances presented by these stomach glands are in 

 many respects similar to those of the mucous glands of pharynx and 

 submaxillary gland of dog. The mucous or central cells of the 

 latter differ from the parietal cells of the " crescents" in the same 

 manner as the chief cells differ from the parietal cells of the 

 stomach, viz., in the nature of the intracellular network. 



The epithelial cells lining the duct of the peptic glands are, during 

 digestion, e.ff. in a dog killed one hour after meal, loaded with mucin. 



(b) The glands of tlie pylorus. — Ebstein^ has shown that the 

 cells lining the gland tubes of the pylorus of stomach of dog 

 possess a different character in the state of hunger and in that 

 of digestion ; in the former the cells are of a clear, finely granular 

 contents, their nucleus being flattened and situated next the 

 membraua propria, in the latter the cells are shorter, more 

 opaque, and their nucleus round and situated more towards the 

 centre of the cells. Ebstein has also pointed out that although 

 the cells lining the pylorus-glands contain a certain amount of 

 mucus, they are not mucus-secreting cells like those of the 

 ordinary mucous glands, with which they have generally been 

 compared, but are to be placed in the same category with the 

 chief cells of the glands of the fundus. Beutkowski - confirms 

 Ebstein's observations. 



I am in a position to confirm these assertions of Ebstein, in 

 so far as I find the cells lining the pyloric glands of dog pre- 

 senting two different aspects according to the state of the 

 stomach. First, the cells are found to be transparent, slender 

 columnar cells with a cup-shaped nucleus pressed against the 

 membrana propria ; the cell substance is a distinct network of 

 fibrils, the meshes containing a clear homogeneous substance. 



' ' Archiv f. Mikrosk. Anatomie,' Band, vi, p. 528. 

 2 'Medicin. Zeitung,' Nos. 14, 15, 17 and 18,1876. 



VOL. XIX. NEW SER. L 



