112 MEDULLA 



supported by the following facts. Non-fatal adrenalectomy in 

 dogs, rats, or rabbits causes no hypertrophy of any extra- 

 adrenal chromaphil tissue. 357, 685 If the medulla subserved an 

 important function other than that involving the cortex, one 

 certainly would expect some hypertrophy of this chromaphil 

 tissue. On the other hand, after unilateral adrenalectomy, 

 Stewart and Rogoff 588 found a compensatory hypertrophy of 

 the medulla of the remaining gland. 



The major part of the chromaphil tissue of the mammal in 

 embryonic life occurs outside of the adrenals. This tissue 

 degenerates after birth while the adrenal medulla develops, 

 which speaks for the assumption that the medulla is the func- 

 tionally active part of the chromaphil tissue while the extra- 

 adrenal chromaphil tissue is of little use to the adult organism. 

 These observations indicate that the medulla takes over the 

 function of the extra-medullary chromaphil tissues. The 

 relative inactivity of the extra-medullary tissue is also indi- 

 cated by Ingier and Schmorrs 329 observation that in persons 

 dead of diphtheria, the adrenals may be free of epinephrine 

 while the paraganglia still contain their normal store of this 

 substance. 



