400 PROCEEDINGS OF THE CANADIAN INSTITUTE. 



take a brownish-black tinge in osmic acid, by which also the nucleus 

 is rendered indistinct. 



The cells in the base of the gland are nearly oval, not provided 

 with a process, coarsely granuled, and the large nucleus situated in, 

 the centre of the cell. The granules are to be found equally in all 

 parts of the cell, which, on the whole, takes a slightly darker 

 stain than those of the body of the gland, which are never found to 

 bulge outside the general limit. The former when not in a resting 

 state give an irregular appearance to the base. This was best seen 

 in young specimens of cat-fish which are always feeding. Macerat- 

 ing the mucous membrane of such specimens in Ranvier's alcohol, 

 Miiller's fluid or in a mixture of the latter and serum, appearances, 

 such as Fig. 5 gives, were obtained. There the cells of the body of 

 the gland are rhomboidal in outline and form a pi-etty regular inner 

 border. Those at the base, however, cause a bulging out of the 

 membrane, some being situated in wedge-shaped niches between the 

 other cells. During activity they preserve this form, shi'inking to a 

 certain extent when resting. 



Between the cells of the body of the gland and those of the base,, 

 staining reagents show not the slightest difference, carmine, hema- 

 toxylon, aniline blue, stain all alike in intensity. The slight differ- 

 ence obtainable in osmic acid hardly merits mention. The granules 

 in all are equally coarse, and four or five hours after the introduction 

 of food into the stomach are arranged about the lumen, which in 

 these glands is more or less indistinct. The cells are unprovided 

 with a membrane, and in serum are all spherical, the processes being 

 retracted. They, however, preserve their original forms in Miiller's 

 fluid and Ranvier's alcohol. 



F. E. Schulze 1 describes in Silurus glanis large spherical cells 

 lying in niche-like swellings of the basement membi'ane, and he evi- 

 dently intended a comparison of these with similarly situated cells 

 in higher vertebrates. As Amiurus and Silurus belong to the same 

 family, it is quite probable that these structures are alike in both 

 and that they have no more morphological value than what I have 

 attributed to them. 



Edinger 2 discovered in Perca Jiuviatilis differences in these cells 

 which, however, he does not describe. Still he believes that a dis- 



