REPRODUCTION 



123 



In Uroleptus halseyi, Calkins actually noticed each of the eight 

 macronuclei is "purified" by discarding a reorganization band 

 and an "x-body" into the cytoplasm before fusing into a single 

 macronucleus which then di\'ides into two nuclei. In the more 

 or less rounded macronucleus which is commonly found in many 

 ciHates, no reorganization band has been recognized. A number 

 of observers have however noted during the nuclear division there 

 appears and persists a small body within the nuclear figures, 





■mMim^mmf^m 



Fig. 53. Macronuclear division in Conchophthirus mytili, 

 X440 (Kidder). 



located at the division plane as in the case of Loxocephalus 

 (Behrend), Eupoterion (MacLennan and Connell) and even in 

 the widely different protozoan, Endamoeba hlattae (Kudo) (Fig. 

 49). We owe Kidder for a careful comparative study of this body. 

 Kidder (1933) observed that during the division of the macro- 

 nucleus of Conchophthirus mytili (Fig. 53), the nucleus ''casts 

 out a part of its chromatin at every vegetative division," which 

 "is broken down and disappears in the cytoplasm of either 

 daughter organism." A similar phenomenon has since been found 



