K 



Fig. no. Conjugation of Paramoecium caudatum. [A-C, after R. HERTWIG; Z>-AV after 

 MAUPAS.] (The macronuclei dotted in all the figures.) 



A. Micronuclei preparing for their first division. B. Second division. C. Third division; 

 three polar bodies or " corpuscules de rebut," and one dividing germ-nucleus in each animal. D. 

 Exchange of the germ-nuclei. E. The same, enlarged. F. Fusion of the germ-nuclei. G. The 

 same, enlarged. H. Cleavage-nucleus, (Y) preparing for the first division. /. The cleavage- 

 nucleus has divided twice, "f. After three divisions of the 'cleavage-nucleus; macronucleus 

 breaking up. K. Four of the nuclei enlarging to form new macronuclei. The first fission soon 

 takes place. 



Q 225 



