958 INFLUENCE OF DUCTLESS GLANDS ON METABOLISM. 
Conclusions. — It may be considered probable that the suprarenal 
capsules are continually secreting into the blood an active material, which, 
although present in that fluid only in minute quantities, may yet be suf- 
ficient to produce very distinct effects upon the metabolic processes of 
muscular tissue, and especially the muscular tissues of the vascular 
system. It has, in fact, been stated by 
Cybulski, and this statement has been 
confirmed by Langlois and by Biedl, 1 that 
the blood of the suprarenal vein contains 
a sufficient amount of the active prin- 
ciple of suprarenal extract to produce a 
marked rise of blood pressure when intra- 
venously injected. I have, in spite of 
careful experiments, not been able myself 
to confirm this statement. Nor is it 
easy to understand how it can be true, 
4. since such blood is constantly flowing 
B. 
Fig. 92. — A. Ergograph tracing of a person suffering from Addison's disease. 
B. Tracing from the same person after six weeks' treatment with suprarenal 
extract. — Langlois.. A, natural size ; B, reduced to one-half. 
into the vena cava in larger quantity than these observers injected. 
But whether we. are able to show it experimentally or not, there is 
very little doubt of the fact that the materials formed pass somehow 
or other into the blood ; and when we compare the results of supra- 
renal injection with the effects obtained from the removal and from 
disease of these organs, we can come to no other conclusion than 
that we have before us a notable instance of internal secretion ; and 
that the effect of such secretion passed into the blood is beneficial 
to the muscular contraction and tone of the cardiac and vascular 
walls, and even of the skeletal muscles, appears very evident from 
the results both of removal of the organs and of injection of their 
extracts. 2 
1 Arch. f. d. ges. Physio!. , Bonn, 1897, Bd. lxvii. 
- This conclusion, which is the one arrived at by Oliver and myself, is different from that 
of Abelous and Langlois, which they formulate thus : — -"Les capsules surrenales out pour 
fonction de neutral iser on de detruire des substances toxiques e'labore'es au cours des 
echanges chimiques et specialement au cours du travail des muscles." This statement, 
which may be taken to set forth the auto-intoxication theory (supra, p. 949), was made in 
1891, and therefore before the effects of injection of the extract of the medulla were known. 
