EFFECTS OF IRRADIATION ON BEHAVIOR AND BLOOD 693 



3 in. above the regular cage floor at feeding time. Uneaten food fell through 

 this coarse mesh to the regular cage floor, from which it was collected for 

 weighing. A fine copper screen inserted between the floor and the bottom of 

 the cage insured collection of all rejected food. A Kennard-Ruch-Fulton 

 watering device was attached to each cage, with graduated reservoirs so that 

 water use could be accurately determined. 



The monkeys were placed in these cages at least 4 weeks before preirradia- 

 tion data were recorded. All measurement procedures except blood sampling 

 were carried out during this conditioning period. Data were gathered for 

 1 week before and 6 weeks after irradiation. 



Food and Water Intake 



Every morning the monkeys received one-fourth of an apple, one-fourth 

 of an orange, and half of a carrot, and these were usually entirely consumed. 

 In the afternoon, more Purina dog chow than the monkey would eat 

 was left in the cage for 1^2 hours. This diet was supplemented periodically 

 with cod liver oil on a lump of sugar. To remove any moisture from the 

 chow, it was placed in a drying oven at 68° C for 24 hours. The remains of 

 the daily ration recovered from the food cup and the fine screen were also 

 dried for 24 hours. The diff'erence in weight between the dried daily rations 

 and the dried remains was considered the animal's food intake for the day. 



Since playful splashing can obscure actual intake, water was available to 

 the monkeys only during three 15-minute periods — at the beginning of the 

 feeding period (after 22/2 hours of deprivation), in the middle of the feed- 

 ing period, and at its end. Since satiation was apparently approached during 

 the first period and splashing occurred during the last two periods, the 

 water intake of only the first periods was considered. 



Activity and Manipulation 



The method of activity measurement was selected after studying four 

 methods with respect to validity and reliability (Fig. 1, see also Isaac and 

 Ruch, 1956). The electric eye method was chosen on the basis of conveni- 

 ence. Briefly, an infrared light beam bisected the length of the living cage. 

 When this beam was broken, a photoelectric cell was activated to drive a 

 digital counter located in another room. The counters were photographed 

 every 20 minutes throughout the day and night with a Grass kymograph 

 camera. 



Pedometers encased in clear plastic were left in the cages except during 

 the afternoon feeding period. When the monkey handled the pedometer in 

 such a way that it was jiggled along its vertical axis, the counting dials were 

 activated. The pedometer scores were recorded once a clay and are an 



