PERIODIC REORGANIZATION OF P. CAUDATUM 



63 



morphological structure is characteristic of beginning reorgani- 

 zation. As this phenomenon approaches the micronucleus fails 

 to take up its accustomed place, and remains free in the cy- 

 toplasm, while the chromatin of the micronucleus seems to 

 assume the form of short bands. Figures 3 and 4 show two 

 animals in the 203d generation from different sub-lines of Cul- 

 ture Y just when the process of reorganization begins — the 

 formation of bands of chromatin, and the wandering of the 



Text fig. 2 Culture Z, Line I, 38th generation, October 12, 1914 



micronucleus in the cytoplasm, indicating the definitive onset 

 of the process. This wandering of the micronucleus has been 

 described by us in the reorganization of Paramaecium aurelia 

 ('14, III, figs. 3, 4, 5). 



Projections of the macronucleus which extrude at a very early 

 stage of the process of reorganization in Paramaecium aurelia 

 have not been seen in our races of Paramaecium caudatum. 



