252 Papers from the Department of Marine Biology. 



Such movement of the plasmosome must depend largely upon growth 

 changes and readjustment in the nucleus which favor its passage 

 through the achromatin. It certainly takes place very slowly, as can 

 be inferred by examining the table of experiments, and the irregularity 

 and slowness of the process seem to confirm the hypothesis that it is 

 not a vital factor but a sort of by-product or accidental and unimpor- 

 tant feature of the development of this cell. 



Magini's observations may be assumed to be correct, but the mis- 

 fortune of finding an orientation in the fish that he vivisected and none 

 in those which had been allowed to die without a strong previous use 

 of the electric organs led him to formulate an incorrect if attractive 

 theory. His further statements concerning the meniscoidal spaces at 

 the dorsal side of the nucleus after great electrical activity were in- 

 correct, as it was osmotic action that caused this condition the action 

 of either the fixatives or the subsequent alcohols. 



The part played by the electric current in the physiology of this cell 

 is probably negligible. While very strong currents did move the 

 plasmosome or appear to control its position to a limited degree, the 

 weak currents did not seem to influence it in any way. Gravity thus 

 seems to be the cause of the orientation in question, which is not 

 accomplished in this fish until later adult life, and is then a more or 

 less variable factor of its structure. 



