62 



NEUTRON EFFECTS ON ANIMALS 



tubes of corn were irradiated with 53-160 n. The average length of the 

 primary roots, 102 hours after germination, was 109 mm. for 19 control 



1000 2000 3000 



NEUTRON DOSE 



4000 



5000 



Fig. 2. Comparison of growth of primary roots after irradiation with fast neutrons 

 and after lower energy neutron irradiation. # = fast neutrons. D = lower energy 

 neutrons. 



plants and 113 mm. for 64 irradiated plants. While this difference in the 

 primary roots, taken alone, was not large, the picture changetl when the 



