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PROTOZOOLOGY 



that during the nuclear division there appears and persists a small 

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

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

 Connell) and even in the widely different protozoan, Endamoeba 

 blattae (Kudo, 1926). Kidder (1933) observed that during the division 

 of the macronucleus of Conchophthirus my till (Fig. 56), the nucleus 

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

 which "is broken down and disappears in the cytoplasm of either 



Fig. 56. Macronuclear division in Conchophthirus mytili, X440 (Kidder). 



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), Allosphaerium convexa (Kidder and Summers), Colpoda 

 inHata, C. maupasi, Tillina canalifera, Bresslaua vorax, etc. (Burt et 

 al., 1941). Beers (1946) noted chromatin extrusion from the macro- 

 nucleus during division and in permanent cysts in Tillina magna. 

 What is the significance of this phenomenon? Kidder and his associ- 

 ates believe that the process is probably elimination of waste sub- 

 stances of the prolonged cell-division, since chromatin extrusion does 

 not take place during a few divisions subsequent to reorganization 



