712 ROGER T. DAVIS AND ARNOLD A. McDOWELL 



in preferences immediately after whole body radiation, and Davis (1958a) 

 reported significant difTerences between food preferences of nonirradiated 

 ^ monkeys and those who had received whole body radiation with a mixed 

 source and had survived 14 months. 



The free choice method was used in this experiment (Davis, 1958a) in the 

 WGTA. A board, 28 X 9 in., containing 125 food wells, was placed in the 

 stimulus tray carrier. The wells were arranged in 5 rows of 25 columns and 

 held small pieces of raisins, apples, bread, potatoes, and celery, assigned in 

 predetermined random order. 



No training preceded that given during the 12 days prior to irradiation. 



Radiatio?! schedule training 



Each subject was given one trial on each of the 12 days preceding irradia- 

 tion and on each of the remaining 54 days of the experiment. The tray was 

 loaded with 125 pieces of food; the opaque screen of the WGTA was raised 

 and the subject was allowed to select 40 pieces of food. 



The preferences before irradiation were grossly comparable to those ob- 

 tained by other workers, although direct comparisons are impossible since 

 subjects were allowed only 40 instead of 60 pieces of food on each trial. The 

 order of preference was raisins, apples, bread, potatoes, and celery. Differ- 

 ences between preferences for food were significant, except between raisins 

 and apples. 



No significant changes in preferences could be attributed to irradiation. 



Systematic Observations 



McDowell et al. (1956) studied the behavior of monkeys in their living 

 cages before and after whole body radiation with 400 r x-rays and contrasted 

 their performance with that of sham irradiated monkeys. Their technique 

 was notably different from that used in naturalistic observations, because 

 they maintained continuous recording and included all behavior that was 

 directed toward objects or represented movement. They reported that whole 

 body radiation produced an over all decline in activity and general malaise, 

 with a significant decrease in the relative frequency of self care and a signifi- 

 cant decrease in the relative instance of initiation of aggression. 



More recently, Hammack (1960) described the syndrome resulting from 

 nitrogen mustard poisoning. In eight categories of behavior (McDowell et 

 al., 1956), the syndromes resulting from whole body radiation and nitrogen 

 mustard poisoning were similar, except in time of onset and duration. 



No observations were made before the experiment began. 



