48 
2) Extracts of the interrenal body of Elasmo- 
branchs produce no effect or only a very partial ef- 
fect in the same direction’). 
3) Extracts of the suprarenal bodies of Teleosts 
always give negative results, having no action on the 
blood-vessels?). 
The above results point clearly to the yiew that the interrenal 
of Elasmobranchs and the suprarenals of Teleosts correspond to the 
cortex of Mammalian suprarenal, while the suprarenals in connection 
with the sympathetic in Elasmobranchs correspond to the medulla. 
And this correspondence is physiological as well as 
structural?). 
It thus appears that the medulla of the suprarenal is 
absent in Teleosts (also in Ganoids, see above). This is a 
curious fact, but there seems at present no way of escaping it. 
The facts above narrated are in my opinion worthy of consider- 
ation as an example of an attempt to solve a morphological problem 
by physiological methods. 
November 11tb, 1896. 
1) The explanation of the partial effect sometimes obtained may be 
(1) either that some of the sympathetic suprarenals have got mixed with 
the extract (they lie close together in the body), or (2) that it really 
corresponds with cortical substance which has this effect. I must leave 
this point doubtful for the present. 
2) It is particularly to be noticed that the effect of the supra- 
renal extract is produced upon the blood-vessels of the 
toad, after the brain and spinal cord have been destroyed 
as completely as possible by pithing. It is evident from this 
that the action is directly upon the blood-vessels and not 
indirectly through the central nervous system. This is ScHärEr’s view 
in regard to Mammalian suprarenal, though Cysutskr and Szymonowicz 
maintain the contrary. 
3) Prerrir (loc. cit.) has investigated the physiology of the suprarenals 
in the eel and finds that the organ is a true gland as shewn by com- 
pensatory hypertrophy of one organ after the renoval of the other. But 
he seems to be totally unaware that the known suprarenals of 
Teleosts consist solely of cortical substance. Now we know 
something about the functions of the medulla of the Mammalian supra- 
renal but nothing about that of the cortex. The investigations of Prrrir 
so far prove nothing further about the cortical substance than that, in 
Teleostean fishes at any rate, it is a true. secreting gland. 
