126 THE ROYAL SOCIETY OF CANADA 



sumption that there is in Elasmobranchs nothing corresponding to the 

 cranial cortical body discovered by Giacomini in Teleosts. 



Modern works for guidance of practising physicians are often 

 confused on this point. Thus, Falta,^ refers to our "sure knowledge 

 that the cortical system and the chromaffine system are in like manner 

 important for life . . ." Now, there is no "sure knowledge" 

 thaf the cortical system and the chromaphil tissue are in like manner 

 essential for life, there is in fact every reason to believe that such 

 is not the case. Biedl, whom Falta quotes, has as we have seen, 

 urged that it is the cortex and not the medulla which is essential to 

 life, and the results of our own experiments point strongly in the same 

 direction. 



We attempted to destroy all the medulla without serious damage 

 to the cortex. The first method which suggested itself to us was to 

 treat the interior of the gland with a sterilized five per cent solution 

 of potassium bichromate. This causes the medulla to assume a rose- 

 pink color. A control experiment carried out upon the abdominal 

 chromaphil body showed that this method would be useless, as a 

 method of permanently destroying the activity of the medulla; for 

 though the body stains deeply at the time, the colour is found to have 

 disappeared after the animal has survived for ten days. Thus, it 

 would appear that the destruction of chromaphil tissue cannot be 

 carried out by means of potassium bichromate. 



Cauterization was the method finally adopted. The glands 

 were exposed by an abdominal incision. The left was completely 

 extirpated, while the vien from the body wall crossing the right 

 gland was ligatured on both sides and an effort was made to remove 

 the entire medulla by cautery. In dogs a more extensive extirpation 

 was carried out. The left gland having been removed, half of the 

 right was amputated and the medulla cauterized out from the re- 

 maining half. The animals were allowed to survive for 3 weeks or a 

 month after the final operation. The gland tissue found at the 

 post-mortem examination was stained with Miiller's fîuid and serial 

 sections cut, in order to search for any medullary tissue that might 

 have escaped the operation. 



We have employed thirty dogs, twenty two cats and four rabbits. 

 In all cases where death has been clearly due to the operation, and 

 not connected with accidents such as loss of blood, over-dose of 

 anaîsthetic, etc., extensive damage has been found to have been done 

 to the cortex. In several instances where the whole or practically 



'Falta: "The Ductless Glandular Diseases," Trans. Meyers. Blakiston, Phil., 

 1916. 



