NEUTRON EFFECTS ON ANIMALS 143 



Group II, whose food intake was not restricted, continued to rise through- 

 out the whole period. 



During the pre-irradiation period the average weight increase of the rats 

 of the 3 groups was identical. Immediately after irradiation there was 

 a loss in weight in the irradiated animals (Fig. IB). The maximum loss in 

 weight, 6 per cent, was reached on the third day after irradiation. There- 

 after the average weight of the irradiated animals increased daily and 

 paralleled that of the non -irradiated animals. The average weight of the 

 irradiated animals, however, remained approximately 6 per cent below 

 that of the non-irradiated ones. The average weight of the rats of Group 

 III, which were not irradiated but were limited in food consumption to the 



IS 



CO 

 < 



a. 

 o 



10 



220 



180 



UO 



0^ 



o. 





-Y~z 6 io i^T^YS r~2 ^ ^ i^AYS 



siAdiation irradiation 



IRRADIATION 



A B 



Fig. 1a and b. The effect of 56.-1 n on A) daily food consumption and on B) weight of 

 rats. #Irradiated. O Control. DXon-irradiated animals: food intake restricted 

 to amount consumed by irradiated animals. 



amounts eaten by the animals of Gioup I, showed a corresponding loss. 

 The greatest weight reduction of the animals of Group III was reached 

 on the 3rd day and differed by only 0.7 per cent from that of Group I rats. 

 The reduction in the growth rate following neutron irradiation was 

 temporary, and the rate of growth soon paralleled that of the control rats. 

 The actual weight, however, remained below that of the controls in amount 

 equal to the weight loss immediately following irradiation. In this sense 

 the animals failed to recover completely. The reduced food consumption 

 appeared to be responsible for the loss in weight following 56.4 n irradiation. 



EFFECT OF NEUTRON IRRADL\TION ON GASTRIC DIGESTION 



The reduction in food consumption noted in rats following neutron 

 irradiation indicated a disturbance in gastrointestinal function. The ef- 

 fects of neutrons on the digestive process in the stomach of the rat, there- 



