EQUALIZATION OF THE ANIMAL TEMPERATUBE. 435 



are very liable to occur. The explanation of this, as far as 

 we can present any, seems to be the following : When the 

 skin acts to keep down the temperature of the body in sim- 

 ple exposure to external heat, there is no modification in 

 nutrition, and the tendency to an elevation of the animal 

 temperature comes from causes entirely external. It is a 

 practical observation that no bad effects are produced, under 

 these circumstances, by suddenly changing the external con- 

 ditions; but when the animal temperature is raised by a 

 modification of the internal nutritive processes, as in pro- 

 longed muscular effort, these changes cannot be suddenly 

 arrested ; and a suppression of the compensative action of 

 the skin is apt to produce disturbances in nutrition, very 

 often resulting in inflammations. 



