Ill, B, 1 Shaklee: Experimental Acclimatization 13 



Table VIII. — Highest daily maximal body temperatures. Acclimatization 

 (monkey U kept in the sun and in contact with the heated roof) — Cont'd. 



1912. .c. 



March 12 39.4 



March 16 39.8 



March 30 39.5 



Average 39.6 



April" 10, 11 39.5 



April 12, 16 39.5 



April 18 39.9 



April 22 39.5 



April 26 40.1 



Average 39.7 



* During April the required hours for civil service employees were from 7.80 in the forenoon 

 to 12.30 in the afternoon ; hence the monkeys were not usually exposed much beyond noon in 

 this month. Only on days that were expected to be very hot were the monkeys kept out in 

 the afternoon. More will be said about this later. 



It will be seen from Table VIII: (1) That never after Decem- 

 ber 1, the first day on the ground, was the temperature of the 

 monkey found above 40.5° — that is, the combined action of the 

 hot sun and hot roof on the hottest days did not produce as much 

 response in the monkey as did the sun's rays alone on Novem- 

 ber 29, 1911 (a body temperature of 40.5° apparently produces 

 no discomfort in the acclimatized monkey) ; (2) that never but 

 once after December 15, the ninth day on the ground, did the 

 temperature exceed 40°, which is a temperature but little, if 

 any, above the maximal shade temperature of this monkey; (3) 

 that the monkey's temperature never exceeded the maximal 

 shade temperature in February and but once, if at all, in March, 

 and but twice in April, the record hot month. This seems to 

 make it clear that a great deal of the acclimatization took place 

 in the first two days of exposure, November 29 and December 1, 

 that by December 18, the eleventh day on the ground, a rather 

 high degree of resistance had been acquired, and that by the 

 end of the second month the resistance had probably reached its 

 maximum. It also seems to show that the temperature of a 

 thoroughly acclimatized monkey, exposed day after day to the 

 sun in contact with a hot roof, rarely exceeds its maximal normal 

 temperature. 



The history of the monkey thus far indicates in a decisive 

 manner, when the earlier history is compared with the later and 

 when it is compared with the experiments of Aron: (1) That 



