THE SUPRARENAL SYSTEM 143 



manner possible. Many animals bore the extirpation of one 

 gland without any sign of derangement, and lived for months 

 afterwards. After the removal of both glands death invariably 

 followed within two to four days. In two rabbits which lived 

 respectively sixteen and twenty-eight days, there were accessory 

 suprarenals of abo'ut the size of a pea, situated close to the vena 

 cava, below the renal veins. 



These experiments undoubtedly prove that the suprarenals 

 are essential to the life of the organism. For not only was the 

 extirpation of the dislodged organs followed shortly by death, 

 but the operation was performed in such a manner that there 

 were no secondary lesions, and there was no danger of infection. 



The results of experimental extirpation of the suprarenals in 

 rats and guinea-pigs require to be discussed separately. It 

 must be remembered that, in the first accounts which were given 

 of animals which survived the extirpation of both suprarenals, the 

 subjects of the experiments were rats (Harley). 



In a large number of his publications, Boinet lays particular 

 stress upon the fact that grey rats will live for one to six months 

 after extirpation of both suprarenals, whether these are removed 

 separately or simultaneously, though many animals die a few 

 days after operation. Abelous and Langlois explain this peculiar 

 state of things by the fact that, in ten rats out of eleven, two 

 to three accessory suprarenals are present in the neighbourhood 

 of the principal organs and the hinder surface of the renal 

 vein. Boinet next tried the effect of removing these accessory 

 structures as well as the principal organs ; he found that, out of 

 twelve animals, seven survived the operation, and of these some 

 lived for several months. He concluded from this that the 

 vicarious function of these accessory organs is generally over- 

 estimated, and he emphasizes the fact that these accessory supra- 

 renals contained no medullary substance. 



Wiesel found that accessory suprarenals without medullary 

 substance, or, as they would now be termed, accessory interrenals, 

 were present in about 50 per cent, of the rats which he examined. 

 They were situated between the testicles and the lower pole of 

 the epididymis, and he found that, after removal of the 

 suprarenals, these structures undergo compensatory hypertrophy. 

 We shall again refer to the significance of this finding 

 in the light of the remarkable frequency with which rats 

 survive double extirpation of the suprarenals. It must, however, 

 be pointed out that, contrary to the opinions of H. and A. 

 Christiani who found that, after total extirpation of both supra- 

 renals, rats died in ten to twenty hours (out of twenty-nine animals 

 only three survived) white rats, especially male animals which 

 have attained sexual maturity, in the greater number of cases, 

 bear the removal of their suprarenals without evil results. It is 

 evident from this that results obtained from experiments with rats 



