312 S. Vincent, 



The cells which make up the masses and columns of the cortex 

 are mostly polyhedral, but in the most external of the outer layer in 

 the horse and in the dog they are elongated columnar. 



In young animals one sometimes finds that the medulla has not 

 yet become completely surrounded by cortex, but comes to the surface 

 at some point. In the case of the suprarenal capsule of a young 

 rabbit I noted a very interesting appearance. Near that part of the 

 circumferance where the medulla reached the surface was a sympathetic 

 ganglion outside the capsule of the organ. Near to it, also outside 

 the capsule was a mass of cells resembling those of the suprarenal 

 medulla only not so uniformly stained by the bichromate. But no 

 cells which could be called transitional forms were to be discovered. 



X. Development of the Suprarenal Capsules. 



As I have not myself investigated this part of the subject I shall 

 content myself with a brief résumé of the conclusions arrived at by 

 observers up to the present time. This is the more necessary since 

 the study of the development throws so much light upon the minute 

 structure of the adult organ. 



Bergmann [9] and Remak [96] seem to have been the earliest 

 observers of the close relation subsisting between the suprarenal cap- 

 sules and the sympathetic nervous system, Leydig [70] in 1852, 

 pointed out the very intimate connections between the sympathetic 

 and the paired suprarenals of Elasmobranchs and the suprarenal bodies 

 of the Urodela. But Leydig misunderstood the nature of the cortex, 

 stating that it is derived from the medullary cells by the deposition 

 of fat-globules. 



Leydig's views as to the nervous origin of the medulla were 

 strengthened by the researches of Balfour [5] in 1878, who concludes 

 provisionally at this date that the paired bodies in Elasmobranch fishes 

 are the true suprarenals while the interrenal "does not belong to the 

 same system"^). Later, this author changes his opinion [6, 7] and 

 definitely expresses the view that: 'Tn Elasmobranch Fishes we thus 



^) By this, Balfour meant presumably that the interrenal body had nothing 

 to do with the suprarenals. 



