SUMMARY 371 



identical histologic lesions in the brain, adrenals and 

 liver. 



If, instead of an increased transformation of energy 

 through a short period, an individual be subjected to a 

 prolonged period of increased transformation of energy 

 from the diverse causes already mentioned, then we 

 find changes of great significance in the organs of his 

 kinetic system. The thyroid may become hyperplas- 

 tic, as in the case of prolonged infection, pregnancy, 

 auto-intoxication and sexual excitation. In animals 

 and in man, likewise, we frequently find the adrenals 

 enlarged in the breeding season, in pregnancy, in car- 

 diovascular disease, after or during chronic infection; 

 while injections of indol, skatol, leucin, tyrosin or 

 peptone, intense fear and excessive muscular exertion 

 cause an increased output of adrenin. In these states, 

 also, the adrenals contain less adrenin, and the liver 

 less glycogen than in the normal state. 



During pregnancy many organs undergo structural 

 changes. The mammary glands enlarge ; the thyroid, 

 adrenals, brain and liver show increased activity in the 

 transformation of energy and in the neutralization and 

 excretion of acid by-products. In some instances, the 

 organs of neutralization and excretion prove inade- 

 quate ; and in consequence, there result nephritis, 

 high blood-pressure and rapid respiration, and finally 

 eclampsia and death. If, however, the fetus be re- 

 moved, the symptoms at once disappear ; a phenome- 

 non as clearly mechanistic as the cure of auto-intoxi- 

 cation by freeing the intestines of their poisonous 

 contents ; as mechanistic as the amelioration of Graves' 

 disease by the excision of the hyperplastic lobe of the 



