GLANDULAR CELLS OF THE FROG'S PANCREAS 383 



increase in volume and then become separated from the filaments, 

 which remain behind. On the contrary, Hoven, 0. Schultze, 

 Arnold, and Maximow believe that the mitochondrial filaments 

 break down into granules, from which secretion granules are 

 to be derived. On the other hand, there are some (Levi, '12; 

 Mislawsky '11, '13; Ciaccio, '13) who definitely reject the 

 possibility that mitochondria participate, whether direct or 

 indirect, in the formation of secretion granules, regarding the 

 granular decomposition either as pathological (Ciaccio) or 

 as an artificial process. 



b. Nuclear origin. That the nucleus of the salivary and 

 pancreatic glandular cell undergoes changes in shape, position, 

 volume, and chromaticity during the stages of secretion was 

 first noticed by R. Heidenhain ('68, '75, '80) ; in the resting 

 condition of the cell, the nucleus exhibits a shrunken appearance, 

 whereas during activity it is spherical and contains distinct 

 nucleoli. Similar changes have been subsequently observed 

 by various investigators (Schmidt, '82; Hermann, '88; Carlier, 

 '96, M. Heidenhain, '90; Steinhaus, '90) and assumed by some 

 to be due not to the mere accumulation and disappearance of 

 secretion granules, but to an active process associated with the 

 genesis of secretion, without definitely involving a decision as to 

 its mode of participation. 



Some investigators (Macallum, '91; Mathews, '99; Gamier, 

 '00; Carlier, '99, '07; Maziarski, '10) are inclined to assign to 

 the chromatin substance of the nucleus a part in the genesis of 

 secretion, assuming that it passes into the cytoplasm either in 

 a corpuscular or an amorphous state. That Gamier is of opinion 

 that the basal filaments are impregnated by the chromatin 

 substance passed out and that Mathews even regards the fila- 

 ments as the chromatin itself, has been stated before. 



Finally, the nucleolus must be taken into consideration. It was 

 maintained by many investigators, as Ogata ('83), Platner ('89), 

 Melissinos and Nicolaides ('90), Ver Eecke ('95), Laguesse 

 ('99, '00), and others, that the accessory nuclei (nebenkerne, 

 plasmosomes, corps paranuclaires) often found in the pancreatic 

 cell are nothing other than the nucleoli passed out, and that 



