172 INTERNAL SECRETION 



fact to light that after suppression of one capsule, the condi- 

 tion of the second does not render it more favourable for trans- 

 plantation ; it does not, as a priori assumption would suggest, 

 become hypertrophied but, on the contrary, it almost completely 

 perishes. 



The functional capacity of a transplanted suprarenal is tested 

 by removing the second capsule some time after the first. In 

 cases where there was pronounced necrosis of the implanted supra- 

 renal, the animals lived for a short time only after the second 

 operation. In nine cases, animals with only one transplanted 

 suprarenal remained alive for many days and even for months. 

 Subsequent microscopic examination revealed, in these cases, a 

 splendid healing-in of the implanted capsule with new formation 

 and reconstruction of the suprarenal tissue, together with com- 

 plete degeneration of the original peduncle and a new vascular 

 system derived from the kidney. As accessory suprarenals "were 

 in no case present, it is certain that these animals continued to 

 live with their only suprarenal implanted in their kidney and 

 that they showed no pathological signs. But these cases, as well 

 as those of double transplantation, supply another remarkable 

 fact, namely, that the animal has a better chance of life if an 

 interval of about eleven to sixteen days is allowed to elapse be- 

 tween the transplantation of one suprarenal and the extirpation 

 and implantation of the other. Where the interval is longer, the 

 results are frequently unsuccessful. The impression conveyed is 

 that the suprarenal function is so completely taken over by the 

 sound capsule, that the regenerative processes in the second, 

 damaged capsule are retarded. If the sound capsule is injured 

 or removed at a moment when the regenerative process in the. 

 second organ is at its height, the new formation of tissue will 

 receive an additional stimulus. 



Yet another group of experiments comprises those in which 

 the transplantation of both suprarenals is undertaken separately, 

 and one kidney, together with the suprarenal implanted 

 in it, is removed by means of a third operation. Of eleven 

 animals experimented upon, six died after the third operation as 

 the result of suprarenal inadequacy. In each of these cases, how- 

 ever, it happened that the suprarenal removed was well healed in 

 and hypertrophied, while the condition of the second, as seen 

 post mortem, was regressive. Five dogs lived for years after the 

 third operation and showed no pathological signs, and in these 

 instances the extirpated transplanted suprarenal \vas also hyper- 

 trophied. 



The degree of functional activity of the transplanted supra- 

 renal has been further tested, by examination of its adrenalin 

 contents by means of blood-pressure experiments and experiments 

 with frog's eyes. The results showed a complete agreement be- 

 tween the microscopic structure and the adrenalin contents. 



