METHOD OF OPERATION 



121 



1 



a/ ♦ oU 



Figure i8. Diagram of the exchange of nuclear materials at conjuga- 

 tion, in Paramecium. 



descendants of A. It is clear therefore that the nucleus con- 

 tains materials which affect deeply the development and 

 characteristics of the individual containing them, just as is 

 true in higher organisms. 



