BODY TEMPERATURE AND FOOD AND WATER INTAKE 363 



importance for the maintenance of a constant body temperature. The 

 contribution of adrenal and thyroid hormones to the metaboHc response to 

 cold has been demonstrated in several ways. Cold exposure is, for example, 



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Fig. 1. Results of local cooling of the preoptic region at different environmental 

 temperatures in the calm goat, accustomed to the experimental conditions. 

 Shivering was observed only at external temperatures below 18°C. Shivering 

 always stopped if the blood temperature reached 41.5 to 41.8°C. The brain 

 temperature was recorded 4 mm lateral to the surface of the thermode. (From 

 Andersen, Andersson, and Gale, 1962.) 



known to activate the release of thyroid hormone by way of the hypo- 

 thalamo-pituitary axis (von Euler and Holmgren, 1956). Recent experi- 

 ments indicate that the task of the " heat loss centre " is not a purely ner- 

 vous control of physical thermoregulatory mechanisms, but that this 

 " centre " also participates in the control of endocrine factors involved in 

 temperature regulation. Following the onset of cooHng of the " heat loss 

 centre ", goats develop a marked hyperthermia even in the absence of 

 detectable shivering. This hyperthermia persists throughout cooling 



