GLANDULAR CELLS OF THE FROG'S PANCREAS 361 



expressed the view that, though the inner zone of the pancreatic 

 cell becomes alveolar after the extrusion of zymogen granules, the 

 remaining portion of it lacks special structure with the exception 

 of chondriocontes in it. It must be borne in mind, however, 

 that the above investigators and others who accept the homo- 

 geneity of the protoplasm have made their observations either 

 in its fresh state or in osmium preparations. 



2. Many of the investigators believe that the protoplasm con- 

 sists of two substances : spongioplasm or mitom and hyaloplasm. 



It is a matter of course that, when the zymogen granules are 

 dissolved out, the inner zone of the pancreatic cell assumes an 

 alveolar or reticular appearance, as described by Langley ('84), 

 Eberth and Muller ('92), Ver Eecke ('95), Zimmermann ('98), 

 and Arnold (12). It is a mistake, however, to conclude that this 

 is the proper structure of the plasm; for such structure is nothing 

 other than an appearance produced by the accumulation of zymo- 

 gen granules. 



The fibrillar structure in the basal portion of the pancreatic 

 cell was first noticed by Pfliiger ('69), R. Heidenhain ('80) 

 ascribed the striation in question to an appearance due to the 

 presence of canalicules. A similar structure was observed by 

 many of the* subsequent investigators: Eberth and Muller ('92), 

 Ver Eecke ('95), Zimmermann ('98), Mathews ('99), Laguesse 

 ('99), and others. Solger ('94, '96) has found the same thing 

 in the submaxillary gland of man and given the term 'basal fila- 

 ments' to it, and, on the other hand, Gamier ('00), who took 

 salivary glands, pancreas, liver, etc., of different species for study, 

 has related the striation which he named 'formations ergastoplas- 

 miques basales,' to the secretive activity of the glandular cell. 

 Similar structures have been since described under the name 

 either of 'Solger's basal filaments,' or of 'Garnier's ergastoplasm' 

 by various workers, as Mouret ('05), Bouin ('05), Prenant ('10), 

 Champy ('11), Bensley ('11), Arnold ('12), Mislawsky ('13), and 

 many others. Their nature has formed a problem of much dis- 

 cussion. In looking over the literature one can classify the 

 structures hitherto described, according to their form and struc- 

 ture, as follows: a) fine filaments which course in vertical direc- 



