ON THE LYMPHATIC SYSTEM. 173 



(^) — The Coui pound Mucous Glands. 



To the exhaustive description given by Heidenhain, Lav- 

 dovvsky, and others of the structure of these glands, i.e. of the 

 submaxillary and orbital gland of the dog, I have nothing to 

 add. As I pointed out in a former paper {' Quarterly Journal 

 of Micr. Science,' April, 1879) the substance of the mucous 

 cells lining the lumen of the alveoli is a distinct reticulum, the 

 meshes of this reticulum being occupied. in the resting state by 

 a transparent substance, the mucigen of Heidenhain ; during 

 secretion this substance changes into mucin, which in hfcma- 

 toxylin specimens is very marked by its deep purple staining. 

 In some places the intracellular reticulum shows a different 

 arrangement in the inner and outer portions of the cells, being 

 longitudinal in the former and uniform in the latter, but this is 

 not seen in all parts of the gland. And for this reason I must 

 correct my former statement on this subject (' Quarterly Journal 

 of Micr. Science,' 1879, p. 141) to the effect that this different 

 arrangement of the intracellular network is not uniformly 

 present in the whole gland. 



The nucleus of the mucous cells is, cateris paribus, in 

 chromic acid specimens more compressed than in those hard- 

 ened in alcohol ; in the latter instance we find in many cells the 

 nucleus spherical or slightly oval, and containing a uniform 

 delicate reticulum. In both cases we find in many alveoli, that 

 in some mucous cells the nucleus in its inner half has identified 

 itself with the cell-substance, while in others it has altogether 

 disappeared. I consider this as a very strong support to the 

 actual and intimate connection between the intracellular and 

 intranuclear reticulum maintained by me in the above-named 

 paper (' Quarterly Journal of Micr. Science,* 1879). Strieker 

 ('Vienna Sitzungsber.,' June, 1877) has shown that in some of 

 the colourless corpuscles of the frog's blood the substance repre- 

 senting the nucleus is part of the ceU-substance, becoming 

 separated off from this by the appearance of the nuclear mem- 

 brane, and becoming again fused with the rest of the cell- 

 substance after the disappearance of that membrane. The 

 appearances that I find in the nuclei of the mucous cells of the 

 submaxillary gland of the dog, and in the mucous alveoli of the 

 submaxillary of man, are such as to leave little doubt that such 

 is probably also the case in these glands. 



The sublingual of the rabbit, as mentioned above, is of the 

 same structure as the submaxillary of the dog, but the alveoli of 

 the latter are larger than those of the former ; in this difference 

 of size participate the lumen, the mucous cells, and the cells of 



