366 Structure of Mucous Salivary Glands. [May 13, 



very closely resembles that described by Klein,* as shown by mucous 

 •cells after treatment with spirit or with a mixture of chromic acid 

 and spirit. I cannot, however, find a network with such close meshes 

 beneath the limiting membrane. The passage from the close-meshed 

 limiting network to the wide-meshed internal network can often be 

 traced with a good lens, such as Powell and Lealand's ^ oil-immer- 

 sion, with angular aperture 1*45. 



With certain modes of treatment the cell network is not seen, thus 

 when a piece of gland is hardened in osmic acid and subsequently 

 with alcohol, the cell usually appears to consist of faint granules 

 imbedded in the cell-substance. In such cases the hyaline substance 

 and the network are indistinguishable, and the two together may 

 stain and leave the granules unstained. At any one focus the stained 

 •substance will then appear as a close network, and the unstained 

 granules as the meshes of the network. On careful focussing, how- 

 ever, it can be seen that the stained substance is simply the mass of 

 ihe cell in which the granules are imbedded. This is, I think, the 

 -explanation of the close network described by Schiefferdeckerf and 

 by Paulsen^ in certain mucous cells. And that the "network" 

 described by Schiefferdecker is in part the hyaline interfibrillar sub- 

 stance of the cell is indicated by his account of it ; according to him 

 it consists of mucigen. 



The sublingual gland differs in various respects from other mucous 

 glands ; a considerable portion of it consists of " albuminous " cells. 

 According to Klein§ no demilunes are present and the gland tubes 

 have only one layer of cells. This is certainly true of the larger part 

 of the gland; the appearance of two layers of cells in a tube is 

 occasionally caused by the section passing obliquely through a spot 

 where a side tube is given off or where the lumen suddenly alters its 

 oalibre. But whilst none of the tubes have a complete double layer of 

 cells, it is I think an open question whether demilunes are absent 

 from the gland. The sublingual gland has been taken as an especially 

 favourable one in which to observe the disintegration of the mucous 

 cells. I do not find that there is any more evidence of disintegration 

 here than there is in ordinary mucous glands. The mucous cells 

 undergo the same changes as do these in the submaxillary of the dog, 

 ~they discharge hyaline substance and granules, and they form fresh 

 cell-substance. Secretion does not cause any division of nuclei. The 

 x( albuminous " cells probably secrete on nerve-stimulation as do the 

 mucous cells ; in speaking of these cells as " albuminous " cells I only 

 follow the ordinary usage according to which a secreting cell which is 



* " Quart. Journ. Micr. Science," vol. xix, p. 125, 1879 ; vol. xxi, p. 154, 1882. 

 f Loc. cit. 



X Max Schultze's " Archiv," Bd. xxvi, p. 307, 1885. 



•§ " Quart. Journ. Micr. Science," vol. xxi, p. 175, 1882. 



