392 S. SAGUCHI 



they bear striking resemblance in shape to each other. The 

 granules or clumps which are produced by the alteration of 

 zymogen granules appear invariably at the distal border of the 

 cell, close to the lumen, while those derived from the intracel- 

 lular network seem to be extruded into the lumen as well as into 

 the intercellular capillary. 



2. Canaliculi. In preparations fixed in Muller-formalin, 

 bichromate-formalin, Regaud's fluid, etc., and stained with 

 iron- or alum-haematoxylin, the cytoplasm takes on a more or 

 less dark color, while certain nets or canaliculi remain totally 

 unstained. All these structures are not the same thing, but 

 they are grouped into two classes. 



a. I have described in the previous section that there is a 

 relatively well-defined area between the nucleus and the distal 

 cell border, and that the zymogen granules are being elaborated 

 in this area: 'secretogenous area.' On examining this area care- 

 fully in the above preparations, especially in those cells which 

 contain a small number of zymogen granules, we find that there 

 are present canaliculi with clear lumen, which intertwine or 

 anastomose with one another so as to form a sort of network 

 from which similar canaliculi project into the surrounding 

 cytoplasm (figs. 75, 82, 83). The meshes of the network are, 

 in most cases, occupied by small granules, which are nothing 

 other than prozymogen granules or zymogen granules in the 

 earlier stages of development; in other words, the formation of 

 the zymogen granules is taking place in the meshes of the canalic- 

 ular network. 



I am of opinion that the canalicular network is to be identified 

 with the intracellular network in the sense of Golgi; the former 

 merely being the negative of the latter, as already shown by 

 Bergen ('04), Bensley ('11), and others. The substance which 

 constitutes the intracellular network cannot be made manifest 

 by the fixing and staining methods above mentioned, while 

 the surrounding cytoplasm is stained to a more or less extent. 

 A possible transition between the canalicular and Golgi's net- 

 work is brought to light by Flemming fixation and iron-haema- 

 toxylin staining, and is formed partly of solid, partly of canalized 



