THERMOTAXIS IQI 



atmosphere increases heat loss, but at the same time it makes 

 impressions on the cutaneous nerves which, when carried to the 

 centers, excite heat production and thus compensation is estab- 

 lished. A cold bath lowers the temperature because heat loss is 

 increased more than heat production. There is increased radia- 

 tion because of the relatively increased difference in the tem- 

 perature of the body and of the surrounding medium. On the 

 other hand, the cold contracts the capillaries, diminishing the 

 amount of blood exposed to the cooling influence of the water 

 and decreasing the amount of sweat; but these influences tend- 

 ing to inhibit heat loss are not equal to those augmenting it. 

 However, in health, thermotaxis prevents the disturbance of the 

 balance between thermogenesis and thermolysis to any great ex- 

 tent, and the temperature cannot be lowered very much. These 

 are only examples of the reciprocal relations maintained between 

 the production and dissipation of heat, a disturbance of which 

 relations is prevented under normal conditions by thermotaxis. 

 Any change in one process is followed at once by a compensatory 

 change in the other. 



