THEORY OF EVOLUTIOX 



185 



several nuclei and in addition there is scattered 

 material or jDarticles called chromidia that are 



^ 



Fio. 91. Diffluji:ia corona. (After Cash.) 



supposed to he chi-omatic in nature and related 

 to the material of the nuclei, possihly by direct 

 interchange. 



AMien Difflugia divides, part of the proto- 

 plasm j^rotrudes from the opening and a new 

 shell is secreted about this mass which becomes 

 a daughter individual. The behavior of the 

 nucleus and of the chromidia at this time is ob- 

 scure, but tliere is some evidence that their 

 materials may be irregularly distributed be- 



