THE SUPRARENAL SYSTEM 1 71 



From this a chaotic mixture of living and hypertrophied, and 

 regressive and necrosed tissue results. 



The hypertrophied tissue may in a later stage again become 

 regressive and, in some cases, even necrosed. This interchange 

 of proliferation and regression goes on for some time, and 

 necrosed tissue may be observed for as long a period as three 

 months. The newly-proliferated cell agglomerations may assume 

 the structure characteristic of the normal suprarenal ; or there may 

 be a re-arrangement, not only in the cells of the cortex, but also 

 in the relative position of the cortex and medulla. The medullary 

 substance frequently breaks through the cortex and forms en- 

 closures between the cortical cell complexes ; or these enclosures 

 may be placed sub-capsularly, and even extra-capsularly. In 

 many instances the regenerated cortex, when complete, assumes 

 a form similar to that of suprarenal adenoma. It was formerly 

 believed that, in successful transplantation, the cortex only re- 

 mained intact, but it is now certain that the medullary substance 

 also retains its vitality and its capacity for regeneration, and that 

 it undergoes hypertrophy in the same manner as the cortex. 



About five months after transplantation, the alternation of 

 regenerative and degenerative processes ceases and the conditions 

 become more stable. In the majority of cases an entirely new 

 suprarenal has been formed; by proliferating into the old structure 

 and becoming regeneratively hypertrophied, the new cortical and 

 medullary tissue crowds out the regressive, necrosed tissue and 

 replaces it. 



The tests which have been made of the functional capacity of 

 the transplanted suprarenal yield the following results : In experi- 

 mental one-sided transplantation and this applies to cases where 

 the histological findings are unequivocal it is not possible to 

 pronounce upon the functional activity of the healed-in organ, for 

 there is always the possibility of the function having been under- 

 taken by the sound one of the pair. One-sided implantation is 

 usually borne without symptoms by dogs, rabbits and cats, 

 v. Haberer describes a control-experiment with a dog, in which 

 one-sided suprarenal extirpation was accompanied by distinct 

 symptoms of suppression, namely, pronounced spastic paresis of 

 the hind extremities, failing appetite and general depression. The 

 dog died at the end of eight days, the post-mortem examination 

 showing that the second suprarenal was slightly hypertrophied. 



In a second group of experiments, both suprarenals were 

 transplanted into the kidney, each capsule being transplanted 

 separately and a varying length of time allowed to elapse between 

 the two operations. In many cases, where the first suprarenal 

 had become necrosed or atrophied and had ceased to function 

 while the preliminary regressive changes were still in progress in 

 the second, the animals died as the result of suprarenal inade- 

 quacy. This group of experiments also brought the interesting 



