ON THE LYMPHATIC SYSTEM. 171 



powers it can be ascertained that this reticulum is present and 

 that the above granules are contained in its meshes. 



Each epithelial cell has in its outer third a spherical nucleus, 

 which in many places, both in preparations hardened in chromic 

 acid and in spirit, is more or less angular. But this state of the 

 nucleus is clearly due to shrinking, because in those specimens 

 where the shrinking is more pronounced, noticeable by the closely 

 packed state and the smallness of the alveoli, also the angular 

 condition of the nuclei is more striking. Such a nature of the 

 alveoli of the cells and their nuclei, as 'figured by Heidenhain 

 (1. c, fig. 3.) i.e. representing the alveoli of the rabbit's parotid 

 in the resting state, cannot for a moment be admitted as 

 typical, for it is due to an excessive shrinking of the gland by 

 alcohol. 



The subm.axillary of the guinea-pig is described by Boll (I.e.) 

 as a mixed gland, and as such is also mentioned by Heidenhain, 

 viz. as a gland, the alveoli of which are lined either only with 

 " albuminous " cells, or only with ^' mucous " cells. This I do 

 not find to be the case, as I have already before [' Quart. Journal 

 of Micr. Science,' January, 1881, p. 115) pointed out. I have 

 shown that the submaxillary gland of the guinea-pig is an albu- 

 minous gland, to which, in the same manner as to the parotid of 

 this animal, is attached a small flattened mucous gland, i.e. the 

 admaxillary inferior, and to which reference has been made 

 above. 



The alveoli of the submaxillary of the guinea-pig have a very 

 small lumen, and are lined with columnar or pyramidal cells of 

 a very similar nature to those that line the alveoli of the pancreas, 

 well known from the observations of Langerhans and Heidenhain, 

 viz. the outer part of the cell-substance containing the spherical 

 nucleus is more opaque than the inner part; in preparations 

 stained with carmine or hematoxylin, the former stains readily, 

 while the inner transparent part does not do so. In the outer 

 part is seen in many places the same kind of longitudinal fibril- 

 lation as described and figured by Heidenhain (L c, p. 174, figs. 

 43 and 44), and as is shown in fig. accompanying this Eeport. 

 The nucleus contains here, as well as in the pancreas, a well- 

 developed uniform intranuclear reticulum ; in some nuclei one 

 or two large particles or nucleoH are seen connected with this 

 reticulum. Owing to this similarity in appearance between the 

 cells of the submaxillary of the guinea-pig and those of the pan- 

 creas, I tried to ascertain whether the former gland contains any 

 proteolytic ferment. I have accordingly cleared it as much as 

 possible of its connective tissue, and after having left it for 

 several hours exposed to the air, I have subjected it to the pro- 



