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Comments 



Auerbach: If UV produced mutations only at gene replication, then 

 all lactose mutants on EMB agar should be sectored. As far as I remem- 

 ber Witkin's experiments, she obtained mainly whole-colony mutants 

 when nuclear number in the treated cells had been reduced to one. 



Strauss: The operational definition of mutation is that it is an inherited 

 change. It is therefore required that any change be subjected to the 

 test of reproduction. One might conceive of an alteration in DNA that 

 produced a change in heterocatalytic activity but which could not be 

 reproduced. We could not call this a gene mutation. At this level the 

 discussion is one of semantics. 



Doctor Auerbach has pointed out a very surprising experiment and her 



