PERIODIC REORGANIZATION IN PARAMAECIUM 491 



Since the process results in the dissemination of the mate- 

 rial from the old macronucleus and the so-called reduction micro- 

 nuclei in the cell, it gives the opportunity for a rearrangement of 

 the molecular constitution of the cell. This involves a more 

 profound intermingling of nuclear and cytoplasmic substances 

 than is possible during the typical vegetative life of the cell. 

 Since this intermingling occurs within a cell we term this reorgani- 

 zation process endomixis. Endomixis is followed by a slight 

 acceleration of cell phenomena and a new rhythm is initiated. 



Similarly, since the consummation of conjugation also results 

 in the dissemination of the old macronucleus and of the 'reduc- 

 tion' micronuclei in the cell it affords the opportunity for a 

 rearrangement of the chemical constituents of the cell. But, 

 further, the exconjugant is supplied with a new nuclear apparatus 

 presumably derived equally from each conjugant. Thus here the 

 introduction of foreign chromatin and possibly cytoplasmic mate- 

 rial affords still greater opportunity for chemical rearrangement. 

 Therefore conjugation is a caryomictic phenomenon where'as en- 

 domixis, characterized by the non-formation of a syncaryon, is 

 an apocaryomictic process. 



The general physiological effect, however, of conjugation in 

 Infusoria is not demonstrated conclusively, though Calkins offers 

 considerable evidence which indicates that, after its consumma- 

 tion, all the processes of the cell, including reproduction, proceed 

 with greater vigor, thus substantiating the view of Blitschli, 

 Maupas, Hertwig and others. Jennings' results on the other 

 hand afford no support for this conclusion. 



Without considering this debated question, however, it is evi- 

 dent from this culture that syngamy in Paramaecium is not 

 necessary, under proper environmental conditions, for the con- 

 tinued life of the race, and therefore that the formation of a 

 syncaryon, composed of material partly derived from another 

 cell, is not a sine qua non for a proper continuation of all the 

 vital activities of the cell. We would therefore put emphasis 

 on molecular rearrangement as the result common both to endo- 

 mixis and to conjugation. Since accelerated vital activities fol- 

 low this chemical change afforded by endomixis, it seems clear 



