716 ROGER T. DAVIS AND ARNOLD A. McDOWELL 



TABLE III 



Mortality during First Year 

 AFTER Radiation 



Monkey and Survival time 



group (days after radiation) 



A-1 radiation 1 + 7 



A-2 radiation 1 + 7 



A-3 radiation 1 + 26 



A-4 radiation 2 + 7 



A-5 radiation 2 + 178 



A-6 radiation 2 + 198 



A-7 Surviving 



P-1 radiation 2 + 134 



P-2 radiation 2 + 160 



P-3— 6 Surviving 



AP-1 



AP-2 



AP-3 



AP-4 



AP-5 



AP-6 



C-1— 9 Surviving 



Discussion and Summary 



The findings broadly indicate the course of damage to the central nervous 

 system by ionizing radiations, suggest relevant areas for further research, and 

 aid in the understanding of the syndrome that results from whole body 

 radiation. 



It is clear that x-ray radiation to parts of the heads of monkeys, in two 

 3,000 r doses spaced a month apart, does not have the same effect on per- 

 formance as surgical insult to comparable areas of the brain. Effects similar 

 to those found in brain-injured monkeys do appear, however, among 

 monkeys that survive a year or more. This is in accord with the report by 

 Arnold et al. (1954) of long latencies between irradiation and histologic 

 changes in the brain. 



The present study indicates that damage from irradiation of the central 

 nervous system is manifest earliest as disturbances of movement, activity, 

 and visual survey. The elevator task requires subjects to make delicate, two- 

 handed, coordinated movements and is the only task to difTerentiate the 

 performance of subjects in the experimental and control groups. 



Subjects given radiation to the frontal lobes showed hyperactivity within 



