THE ADRENAL BODIES 153 



inter-renal of Elasmobranchs that after its extirpation the 

 animals can live two or three weeks, and then die with symp- 

 toms of general prostration, just as do mammals after extir- 

 pation of both dual adrenals. Again, he concludes that 

 the cortex is the essential part. These experiments upon 

 Elasmobranchs must be very difficult, but so far they certainly 

 seem to point to the cortex as the vitally essential tissue. 

 The validity of these experiments is, of course, based upon 

 the assumption that there is in Elasmobranchs nothing 

 corresponding to the cranial cortical body discovered by 

 Giacomini in Teleosts. 



Some recent experiments carried out in my laboratory by 

 Mr. T. D. Wheeler lend considerable support to the view that 

 it is the cortex and not the medulla which is essential to life. 

 Instead of attempting to remove the cortex and leave the 

 medulla, Wheeler's object was to cauterize out the latter and 

 leave the former. This was scarcely ever precisely achieved, 

 but a systematic histological study of the glands after death 

 showed that entire destruction of the medulla of both glands 

 gives negative results. The only fatal cases (at any rate 

 among the animals which could reasonably be supposed to 

 have died of adrenal insufficiency) were those in which very 

 considerable damage had been done to the cortex as well as to 

 the medulla. In some cases the abdominal chromaphil body 

 was removed as well as the adrenal medulla. Of course in 

 such experiments groups of sympathetic chromaphil cells, as 

 well as scattered cortical " accessory " bodies, must have been 

 left behind. But this fact does not seriously affect the logic of 

 the argument that it is the cortex which is essential to life. 

 For, since removal of both adrenal bodies is fatal, and removal 

 of the medulla is not, it follows that the cortex is the essential 

 part of the gland so far as the maintenance of life is concerned. 

 We have seen in a previous section that the cortex is the more 

 important from a morphological standpoint. 



It seems, then, that the symptoms observed in animals after 

 adrenal extirpation, complete or partial, are by no means 

 characteristic. The anatomical line which separates full 

 physiological sufficiency from fatal insufficiency is very 

 narrow. It has not been possible to produce experimentally 

 any well characterized symptoms associated with partial 

 adrenal insufficiency. 



