152 



PHYSIOLOGY 



These observations show an increase in body temperature 

 with an increase in room temperature up to 30° C. at the rate of 

 0.7°C. for the body in response to 5°C. increase in the room 

 temperature. 



On change of surrounding temperature the adjustment of the 

 caloric output lags. Thus rats brought from a cold to a warm 

 room have a higher body temperature than rats habituated to 

 the warm room, Przibram (Personal, 1923). 



The rat therefore regulates but poorly its body temperature 

 and is somewhat poikilothermous. 



(d) Calorimetry. According to the experiments of Hill and 

 Hill ('13) a fasting rat of 100 grams gives out approximately 

 20 calories per day. The ratio H/W (H = total heat; W = body 

 weight) is fairly constant above 90 grams in body weight, i.e. 

 the fasting heat production is directly proportional to the body 

 weight. 



