14 ANATOMY 



resemble those of the Stannius' corpuscles, (their homologues 

 in the teleost fishes) and the adrenal cortex of the higher 

 vertebrates. 



The chromaphil tissue of the elasmobranchs occurs in the 

 form of segmentally paired bodies arranged on branches of the 

 aorta in close relation to the ganglia of the sympathetic 

 chain. 649 



Direct evidence exists for the physiological identity in func- 

 tion of the chromaphil bodies and the adrenal medulla. Thus 

 Vincent 646 ' 647 ' 648 showed that the saline extracts of these bodies 

 in the dogfish had vasoconstrictor and pressor activity similar 

 to that of extracts of the adrenal medulla. Similar extracts 

 prepared from the interrenal bodies manifested no such actions. 

 Vincent's observations were confirmed by Biedl and Wiesel 57 . 

 Lutz and Wyman 409 demonstrated the mydriatic action of 

 extracts of the chromaphil tissue of certain elasmobranchs, 

 which is indicative of the elaboration of epinephrine by these 

 bodies. Extracts of the interrenal body, on the other hand, 

 were free of any sympathomimetic activity. 



The homology of the interrenal bodies of the elasmobranchs 

 with the adrenal cortex has also been proven by physiological 

 experiments. Thus Biedl 56 demonstrated that removal of the 

 interrenal bodies in the skate and the torpedo results in symp- 

 toms (weakness, pallor, cachexia, etc.) and ultimate death 

 analogous to that observed after removal of the adrenal cortex 

 in higher animals. Kisch 353 confirmed and extended these 

 observations. The operative difficulties involved in perform- 

 ing interrenalectomy in fishes renders conclusions based on 

 extirpation experiments of doubtful value. Less equivocal 

 evidence was obtained by Grollman, Firor, and Grollman 260 

 who demonstrated that extracts of the interrenal body of the 

 skate (Raja stabuliforis, Raja diaphanes, and Raja erinacea), 

 when administered to bilaterally adrenalectomized rats, mani- 

 fested a complete replacement therapy. 



In the teleost fishes the interrenal bodies occur as small 



