454 LORANDE LOSS WOODRUFF AND RH. ERDMANN 



completely free from disintegration products of the old macro- 

 nucleus, is often not completed before the third division. All 

 descriptions of the behavior of the paramaecium cell of the 

 different species after the formation of the syncaryon agree in 

 the origin of four or eight new micronuclei, but these micro- 

 nuclei resulting from the syncaryon are either all used in the 

 further development of the cell (Calkins and Cull, Paramaecium 

 caudatum; Maupas, Hertwig, Woodruff and Erdmann, Para- 

 maecium aurelia; Hamburger, Paramaecium bursaria), or some 

 degenerate (Maupas, Klitzke, Paramaecium caudatum; Doflein, 

 Paramaecium putrinum). Therefore the weight of evidence at 

 hand indicates that the latter alternative is due to a wrong inter- 

 pretation. Similarly in the process under discussion in Para- 

 maecium aurelia there is no evidence of a wasting of chromatin 

 material in this period and its morphological features are iden- 

 tical with all statements of the nuclear changes in typical con- 

 jugation in this species. 



The observations of Hamburger on Paramaecium bursaria prove 

 that the first micronuclear division after the development of 

 the anlagen may occur either in the old cell or later in the two 

 daughter cells which arise from it. Before the first cell division 

 in the reorganization process two spindles are formed (fig. 22, 

 pi. 2) which indicate that the first cell division after the forma- 

 tion of the macronuclear anlagen restores the normal nuclear 

 apparatus of the cell. During the next two generations the rem- 

 nants of the old macronucleus are completely eliminated. This 

 is effected by complete dissemination in the cell of the chromatin 

 bodies (fig. 27, pi. 3) in the form of cloud-like masses of faintly 

 staining chromatin granules which soon undergo total involution 

 in the cytoplasm. This disintegration process does not occur 

 simultaneously in all the chromatin bodies as is shown in the 

 figure under discussion in which four bodies are still intact. 



The animals which have undergone their first vegetative divi- 

 sion are filled with vacuoles as shown in an animal from Line 

 Illb, 4313th generation (fig. 27, pi. 3). The macronucleus has 

 assumed the peculiar spherical form which it frequently shows 

 immediately after cell division. - The climax was in the 4312th 



