520 



DOROTHEA STARBUCK MILLER 



SH1V30 JO 



Fig. 2. Latency of fatal audiogenic seizures in Fi female mice. Comparison, during 

 two periods, of latency in controls and groups irradiated at 350 mrad per day. Mice 

 were born on the dates indicated and were tested 30 days later. Low background 

 prevailed from December, 1956 to April, 1957. From April, 1957 to October, 1957, 

 the backgroimd was considerably higher. 



