H 



K 



Fig. 131. Conjugation of Paramcecium caudatum. [A-C, after R. HERTWIG; D-K, 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 r6but," and one dividing germ-nucleus in each animal. D. 

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

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

 has divided twice, y. After three divisions of the cleavage-nucleus ; the macronucleus is breaking 

 up. K. Four of the nuclei enlarging to form the new macronuclei. 



