KFFKCrr OF X IRRADI MION O.N JHK MOUSE FOETUS 



eight- to nine-day period, where the rate of development is changed owing to 

 environmental circumstances ? 



Dr. Fr.\ser: Ves, I think this would be very interesting in terms of the growth of the 

 organism. Our way of going into this is not so much to change the environment, 

 since there is quite a sufficient fluctuation of growth rate in mice. Instead we plan 

 to irradiate and then remove the foetus two to three days after exposure, when we 

 could make accurate measurements on its growth rate at that time of exposure, and 

 determine whether we were getting any fluctuation of sensitive period by this means. 

 This would cover your suggestion. 



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