The Comparative Histology of the Suprarenal Capsules. 317 



No physiologically active principle can be obtained from it. Pettit [89] 

 has ascribed an antitoxic function to the suprarenal bodies of the 

 eel, which I have shewn to consist only of the representative of the 

 cortex ^). 



11. The suprarenals are very intimately related to the blood- 

 vascular system. This relationship is most striking in Elasmobranchs, 

 but is still evident in Mammals from the very large blood-supply to 

 the organ and its close anatomical connexion with the great veins. 



12. The cortex, from a morphological stand point ivould seem 

 to he the more important or essential element of the suprarenal gland. 

 For it is always more abundant in amount than the medulla, and 

 is universally present in all animals above the very lowest Verte- 

 brates, whereas the medulla appears to be absent in some orders of 

 fishes'-). 



The following table is intended to represent in a compact form 

 the variations in occurrence and arrangement of the suprarenal con- 

 stituents throughout the Vertebrata, so far as is known at present: — 



^) This harmonises well with some interesting results obtained by Myers 

 (Brit. Med. Journ. 1898. April 9. p. 946) witli regard to the action of tissue 

 extracts on cobra poison. His experiments were made with the organs of guinea- 

 pigs, and with tlie result that the suprarenal body was alone found capable of 

 neutralising the cobra poison. Positive results were also obtained with the supra- 

 renal of the sheep , the only other animal tried. The interesting feature of these 

 experiments is that the medulla was found to he inactive, the cortex and the entire 

 gland active. 



') In the present state of our knowledge the medulla must undouljtedly be 

 considered as the more important from a physiological standpoint. 



