TOWARD A GENETICS OF STENTOR 



g: anaphase separation. 



h: chromosomes reach poles as granules, and spindle body 

 disappears. 



5. Nuclei near the partition may be the sexual nuclei, con- 

 siderably reduced in size from reduction of chromosomes to 20 

 by maturation division. Further division figures and degenerating 



mitoses elsewhere. 



6. Exchange of migratory pronuclei. 



7. Fertilization and first 2 divisions of the amphinucleus. 



a: male pronucleus becomes surrounded by halo of 



cytoplasm. 

 b: halo carried with it as it penetrates partition into the 



partner cell. 

 c : nucleus with chromatin massed forward breaks free from 



halo. 

 d: union of male pronucleus with female, which is larger 



and more loosely formed. 

 e: fertilization spindle figure, always surrounded by a 



thickened cytoplasmic halo.- 

 /; termination of this first division. 

 g: beginning of second division, with parachute-form 



nuclei. 

 h: division produces 4 similar products. 



8. Partners, each with four new nuclei, now separate. 



w 



