OF MICR O- OR CAN ISMS. 



117 



Fig. 7 d. Gemmiform conjugation of the Vorticellinae (Carchesium poly- 

 fa'num). A, first stage: the microgonidium mi has fastened itself by a filament 

 upon the peduncle of the macrogonidium. B, a more advanced stage: the mi- 

 crogonidium has fastened itself directly upon the body of the macrogonidium, 

 and its substance begins to penetrate into the latter. In both individuals the 

 nucleus has separated into small rounded fragments, and in the microgonidium 

 are seen the two striated segments resulting from the division of its nucleolus. 

 C, last stage of the conjugation. The microgonidium, completely void of its 

 contents, remains attached to the body of the macrogonidium under the form 

 of a minute hollow tube, which in the end drops away, ma, macrogonidium; 

 mi, microgonidium; n, nucleus; nu, nucleolus; v. c., contractile vesicle. (Figures 

 from M. Balbiani.) 



