THE SUPRARENAL SYSTEM 269 



the following : The removal of the cortical substance providing 

 al \\ays that it is not replaced by the vicarious intervention of 

 highly developed accessory interrenals, as in some animal species, 

 notably rats is not consistent with the continuance of life. 



Some interesting anatomical data are to hand. Elliott and 

 Tuckett compared the weight of the suprarenals in different 

 animals and found that, as a general rule, the size of the supra- 

 renal increases with the weight of the body and with the develop- 

 ment of the muscles. They found, moreover, that the increase 

 in the size of the organ is principally due to an increase in the 

 cortical portion. The lower the status of the species in the order 

 of vertebrates, the larger in proportion is the adrenal system and 

 the part which it plays in the formation of the suprarenal ; while, 

 at the same time, the amount of interrenal tissue, and especially 

 the suprarenal cortex, is proportionally reduced. There is, more- 

 over, an increase in the volume of the suprarenal cortex in the 

 course of the development of the individual. The medullary sub- 

 stance increases only slightly with the growth of the individual, 

 but the volume of the cortical substance becomes very much 

 augmented. In the guinea-pig, for instance, a five-fold increase 

 in the weight of the body is accompanied by a twelve-fold increase 

 in the weight of the suprarenal cortex, the medullary portion re- 

 maining practically unchanged. The exceptional size of the 

 suprarenals is characteristic of guinea-pigs and is almost entirely 

 the result of extreme development of the cortical part, this portion 

 being in the guinea-pig nearly ten times as large as in the dog. 

 The increase in the size of the cortex during extra-uterine growth 

 is also observed in the cat, dog and rabbit. 



A still further growth of this portion of the suprarenal takes 

 place during pregnancy. Suprarenal hypertrophy in pregnancy 

 was first observed by Guieysse in guinea-pigs and has since been 

 observed in animals of different species (Stoerk and v. Haberer) 

 and in man. This hypertrophy is not entirely the result of an 

 increase in the cortical substance, although the cortex is the part 

 chiefly affected. There is at the same time an increase in the 

 chromaffine cells, in which numerous karyokineses are observed. 



The similarity between the cells of the suprarenal cortex and 

 those of the corpus luteum verum is specially commented upon 

 by Mulon, Wallart and others. Mulon even regards the corpus 

 luteum verum as a temporary suprarenal cortex. 



That there is a connection between the suprarenals and the 

 activity of the sexual glands, is shown by the observations of 

 Marassini, Cecca, and Teodossieff. These authors found that, 

 after castration, there was an increase in the weight of the supra- 

 renal, principally due to hypertrophy of the cortical substance. 

 Marchand describes suprarenal hypertrophy in pseudoherma- 

 phroditism. On the other hand, the observations of Bullock and 

 Sequeira, Adams, Shattock, Linser, Thumin, Brotz, and others, 



