GLANDULAR CELLS OF THE FROG'S PANCREAS 401 



either filamentous or spindle-shaped, crescent- or comma-formed 

 or even spherical. In some cases the structures have been 

 described as being homogeneous. This type is described and 

 figured by Nussbaum ('82), Steinhaus ('90), Macallum ('91), 

 Eberth and Miiller ('92), Ver Eecke ('95), Mouret ('95, '05), 

 Carlier ('96), Mathews ('99), Champy ('11), and others. 



To the second type belong those corpuscles which are spherical 

 in shape and of various sizes. They are either homogeneous 

 or granular, or contain spherical or crescent-shaped bodies. 

 This type is found by Nussbaum ('82), Ogata ('83), Platner 

 ('89), Melissinos and Nicolaides ('90), Macallum ('91), Eberth 

 and Miiller ('92), Ver Eecke ('95), Galeotti ('95), Mouret ('95, 

 '05), Mathews ('99), Gamier ('00), Babkin, Rubaschkin and 

 Ssawitsch ('09), and others. 



b. Origin. Various views advanced concerning the origin of 

 the mebenkern' can be summarized as follows : 



Nuclear origin. Ogata, Galeotti, and Platner believe that the 

 'nebenkern' is derived from the plasmosome passed out of the 

 nucleus; Macallum, Ver Eecke, Melissinos and Nicolaides, and 

 Gamier maintain a nuclear, origin for a part of the structures, 

 while another part is regarded as made up of products of 

 chromatolysis. 



Plasmic origin. Mouret identifies the mebenkern' with the 

 matrix of the cell or his 'prezymogenes;' Carlier also describes 

 the accessory nucleus as indistinguishable from the neighboring 

 dense granular spongioplasm. Eberth and Miiller, Mathews, 

 Melissinos and Nicolaides, and Gamier ascribe to a part of the 

 'nebenkerne' a plasmic origin; according to Eberth and Miiller, 

 they are produced by the adhesion of protoplasmic filaments; 

 Mathews likewise holds that they are nothing other than coiled 

 or contorted cell-threads. However, the question, how they 

 are formed, remains unanswered. In addition, Champy identi- 

 fies the mebenkern' with the sphere of the egg-cell, and 

 claims to have found central corpuscles in its centre. Babkin, 

 Rubaschkin and Ssawitsch, finally, advance the view that the 

 'nebenkern' is derived from zymogen granules. In their experi- 

 mental study, they believe to have found that a plasmic portion 



