360 PRESENT PROBLEMS IN EVOLUTION AND HEREDITY. 



Conjugation begins with the approach of two individuals, and adhe- 

 sion by tlieir oral surfaces. There is no fusion, but an immediate trans- 

 formation in the cell contents of each individual sets in, concluding 



So 



a n 



la 



cS p 





R "§ ■- 



lit! 



SO 



g 2 





with an interchange of nuclear substance. In each cell Maupas dis- 

 tinguishes between the {M) nKganueJeuH (Fig. 10, the macronucleus, 

 nucleus, endoplast of authors), which presides over nutrition and 



