REPRODUCTION 



127 



is "purified" by discarding a reorganization band and an "x-body" 

 into the cytoplasm before fusing into a single macronucleus which 

 then divides into two nuclei. In the more or less rounded macro- 

 nucleus that is commonly found in many ciliates, no reorganization 

 band has been recognized. A number of observers have however noted 

 that during the nuclear division there appears and persists a small 

 body within the nuclear figure, Ipcated at the division plane as in 

 the case of Loxocephalus (Behrend), Eupoterion (MacLennan and 



't^M^. 



Fig. 55. Macronuclear division in Coyichophlhirus mytili, X440 (Kidder). 



Connell) and even in the widely different protozoan, Endamoeha 

 blattae (Kudo) (Fig. 51). We owe Kidder for a careful comparative 

 study of this body. Kidder (1933) observed that during the division 

 of the macronucleus of Conchophthirus mytili (Fig. 55), 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 

 further in C. anodontae, C. curtus, C. magna (Kidder), Urocentrum 

 turbo, Colpidium colpoda, C. campylum, Glaucoma scintillans (Kidder 

 and Diller), and Allosphaerium convexa (Kidder and Summers). 

 Kidder and his associates believe that the process is probably 



