RADIATION DAMAGE TO CHROMOSOMES 209 



HOLLAENDER : It is truc that this question may bo solved only by erossinjf . Tn 

 order to verify it at present the appearance of biochemical mutations and back 

 mutations in E. coll are being studied. 



shabadash: Would you state in a general form that in maminals, beside inter- 

 cepting radicals when cysteamine is used, it is most important to achieve meta- 

 bolic changes? 



HOLLAENDER: Theoretically it is a very complicated problein. 



ASTAURov: What miitations did you record in the work with Pararnecmnil As far 

 as I understood recessive mutations had been followed up, but these nuitations 

 would be masked by the influence of the multiploid nucleus. How were they 

 recorded? 



HOLLAENDER: In Dr. Campbell's work a special strain is used. In this case re- 

 cessive mutations can easily be followed up. 



