230 MAN --AN ADAPTIVE MECHANISM 



in the external environment can be held responsible, 

 the internal environment has usually supplied the 

 disturbing factor, infection or auto-intoxication , for 

 example. I have never known a case of Graves' 

 disease to result from hard physical labor, unattended 



A. 



Section of normal liver of a cat. 



Section of liver of a cat after 

 infection. 



FIG. 53. EFFECT OF INFECTION (STREPTOCOCCAL) ON THE LIVER OF A CAT. 

 Note the general disappearance of cytoplasm and the vacuolated spaces 

 inB. 



(From photomicrographs, X 1640.) 



by " psychic" strain; nor from energy voluntarily 

 and naturally expended. 



Whatever the exciting cause of Graves' disease, 

 however, whether unusual business worry, disappoint- 

 ment in love, a tragedy, a strong fear, the illness of a 



