GLANDULAR CELLS OF THE FROG'S PANCREAS 393 



cords. In conclusion, it must be noticed that the three states 

 of cords, that is to say, one, solid, and the two others canalic- 

 ular with or without the wall, are probably produced according 

 as they are perfectly preserved or are partly or entirely dissolved 

 out. 



b. There can be seen another system of canaliculi in the 

 pancreas cell, which seems to be different both morphologically 

 and topographically from those above mentioned. They are 

 tortuous, fine, clear canaliculi which ascend vertically along 

 the sides of the nucleus and lose themselves in the granular 

 zone or in the secretogenous area (fig. 83). These canaliculi 

 are, to my mind, to be regarded as the negative of the mitochon- 

 drial filaments, which, in the preparations we are dealing with 

 here, remain unstained, while the cytoplasm takes on a mora or 

 less dark color. 



3. Significance and genesis of the intracellular net apparatus. 

 It has been assumed that there are in the pancreas cell two kinds 

 of canalicular systems, one of which is located above the nucleus 

 and is to be identified with Golgi's intracellular network. The 

 question as to whether the intracellular network or canalicular 

 apparatus communicates with the exterior or not has been 

 answered in the affirmative, in contradistinction with the view 

 of Negri ('00), Bergen ('04), and Bensley ('11). We have also 

 been led to the conclusion that the intracellular network con- 

 sists of secreting material which is to be extruded either directly 

 into the lumen or indirectly into the intercellular capillary. 

 The connection which may exist between the network and the 

 intercellular capillary is expected from the other side of observa- 

 tion. As has already been noticed by Langerhans ('69), Laser- 

 stein ('94), and others, the intercellular capillary of the pancreas 

 is a canaliculus which passes between the cells downward and 

 terminates with the blind end before reaching the basal mem- 

 brane. This is made evident in an injection preparation, in 

 which we see that the injected intercellular canaliculus carries 

 on its surface spinous or club-shaped projections, although the 

 intracellular network cannot be injected from the duct (fig. 99). 

 But the existence of these projections would indicate that the 



