164 MAN --AN ADAPTIVE MECHANISM 



temperature of one degree centigrade the metabolic 

 activity in the body is increased ten per cent. This 

 increase in the expenditure of energy is not compen- 

 sated by an increased intake of food, since in acute 

 infection there is aversion to food and often vomiting. 

 In infection, as in fear, therefore, it would seem as if 

 the combined resources of the body were concentrated 

 upon the effort at chemical self-defense ; and in the 

 furious combustion to attain this end the host himself 

 is often destroyed. 



We assume that the mechanism which transforms 

 potential energy into kinetic energy to produce muscu- 

 lar action is the brain-muscular apparatus, assisted by 

 the activating and accelerating organs, the thyroid and 

 the adrenals. We postulate that the mechanism which 

 produces muscular action and emotion is the same as 

 the mechanism which generates heat, maintains con- 

 sciousness, and causes the splitting up of foreign pro- 

 teins by which the chemical purity of the body is 

 maintained. Unless this be true, our argument for a 

 kinetic system fails. 



Histologic Changes in the Brain, the Liver and the Adre- 

 nals in Relation to Transformation of Energy 



If the brain, the thyroid, the adrenals, the liver and 

 the muscles work together in transforming potential 

 into kinetic energy for the adaptive reactions of heat 

 and motion, we should find similar changes in these 

 organs whatever may be the purpose of the conversion 

 of energy whether for the production of motion in 

 running or fighting or for the production of heat in 

 combating infection. We should find also that these 



