46 
It is very satisfactory to note how very closely our results agree, 
especially as we appear to have been working each unknown to the 
other. There are some minor points of difference which need not be 
discussed at present. 
I wish now to point out that I have already gone a stage further 
than DIAMARE. The final sentence of his conclusions will serve as the 
starting point for the further exposition of my views on this subject. 
“— rimanendo poi ancora a provare se, nel fatto, la sostanza midollare 
sia un derivato del simpatico.” This implies that if the “medullary 
substance” corresponds to the paired suprarenals of Elasmobranchs 
then it is a “derivative of the sympathetic”. I have already stated 
above that in my opinion, the relation of the paired suprarenals of 
Elasmobranchs to the sympathetic has been overstated. What DIAMARE 
states for the interrenal, I would state for the paired bodies also, ex- 
cept that the contiguity in the case of the latter is very much greater 
than in the former. In fact I do not consider that either portion of 
the suprarenal is essentially nervous in origin and nature. The 
suprarenal capsule of mammals is a double internal se- 
creting gland, the two parts of which have most probably been 
derived from the two structures which have been called suprarenals 
in Elasmobranch fishes. And these two sets of structures, the inter- 
renal and the paired suprarenals, are both of them, 
internal secreting glands. 
That the interrenal and the suprarenals of Teleosts correspond 
to the cortex of the suprarenal of higher Vertebrates, while the paired 
bodies along the branches of the aorta in Elasmobranchs correspond 
to the medullary, I have already definitely stated in the above table. 
But further evidence may be desirable, and this, I believe, I can bring 
forward. 
Last summer, when exhibiting a series of slides illustrative of 
the comparative histology of the suprarenal capsules at a meeting of 
the Physiological Society, and when I referred to the probability that 
the segmentally-arranged suprarenals of Elasmobranchs corresponded 
to the cortex of the suprarenals of higher Vertebrates, Prof. SchHÄrER 
suggested that I should test the matter physiologically. I have per- 
formed a number of experiments in this direction and the results are 
so interesting and so entirely confirm what I had previously made 
out from histological investigation, that I feel justified in giving my 
results in the form of a preliminary communication. 
It is now well known that extracts of suprarenal capsules, when 
injected into the blood-vessels of a living animal, produce certain de- 
