69S 



T. C. RUCH, WALTER ISAAC, AND ROBERT W. LEARY 



because manipulation by the most heavily radiated animals increased greatly. 

 This increase does not seem reasonable in the light of the scores of the 

 other experimental groups, nor does it agree with the data gathered by 

 Leary and Ruch (1955). While this difference may be real, it is regarded 

 with suspicion. 



Blood Cells 



Anticipating more striking changes in behavior and wishing to make a 

 start at analyzing their cause, we observed the blood picture of the animals 

 intercurrently with behavior testing. Comparatively little was then known of 

 the hematologic effects of sublethal radiation in monkeys (see French et al., 

 1955). Blood samples were taken 3 or 4 days before the radiation day, on 

 that day, 3 days later, and thereafter at weekly intervals for 9 weeks. 



The white blood cell count dropped 24 hours after radiation (Fig. 5), 

 but the difference between irradiated and control animals was not statisti- 

 cally significant. By the 3rd day after irradiation, the mean for all radiated 

 animals was significantly lower than for the control group. This difference 

 was maintained until 28 days after radiation. At that time, there was a 

 statistically significant differential recovery rate among the irradiated groups. 

 The animals that had received the largest dosage of radiation were fastest 

 in recovering, and those that had received the smallest dosage were slowest. 

 Leucophilia was apparent during the next 3 weeks. At 42 days, the mean 

 of the combined experimental groups was significantly higher than that of 



17 14 21 28 35 42 49 

 Fig. 5. White blood cells before and after irradiation. 



