2 So INTERNAL SECRETION 



of the cortical cells and those of all interrenal tissue. What was 

 known of the morphological relationships and the microchemical 

 properties of these granules supplied the material for the investi- 

 gation of their chemical composition. 



This occurrence of peculiar granules in the suprarenal cortex 

 was first described by Simon and Ecker (1846), and has been 

 confirmed by all subsequent investigators. The older authors 

 regarded them solely as fat-granules, and were content to describe 

 their distribution in animals of different species and the quantities 

 in which they were to be found in the different parts of the cortex. 

 According to Kolliker, there are animals, such as carnivora and 

 rodents, in which the amount of fat in the suprarenals is so large 

 that it lends a yellow-whitish colour to the entire cortex. There 

 is also a large amount of fat in the external portion of the cortex 

 in the horse; while in the swine and in ruminants, on the other 

 hand, the cortex is grey in colour, the cells being pale and having 

 apparently little fat. The suprarenal of man occupies a middle 

 place between the two, there being in youth but little fat, though 

 this increases by degrees until finally the entire cortex, with the 

 exception of the inner zone, acquires a yellow-white appearance. 

 The greater number of authors find that the granules, which they 

 believe to be fat globules, are most numerous in the median portion 

 of the cortex; that they diminish considerably in number towards 

 both the inner and outer cortical boundaries; and that the cells 

 of the inner layer contain, in addition to the cortical granules, 

 certain other cell-contents, more particularly pigment. 



Moers and Arnold described the resistance which the more 

 shining of these granules offer to alkalies and acetic acid; "but 

 A. von. Brunn was the first to inquire into the actual nature of 

 these bodies. He found that the numerous shining granules in 

 the cells of the external zone did not dissolve in acetic acid and 

 ether, and that they did not stain black with osmic acid ; he con- 

 cluded from these findings that they could not be composed of 

 fat. For the same reasons, Braun believes that the more strongly 

 refractive bodies in the suprarenal cortex of reptiles are only 

 partially composed of fat. Gottschau also describes the highly 

 refractive granules, present in the inner layer of the cortex in 

 mammals, as insoluble in acetic acid and liquor potassa?. 



A detailed account of the microchemical relationships of the 

 cortical granules was first given by H. Rabl. He found that 

 cortical granules from the suprarenal of the hen were soluble in 

 alcohol, ether and chloroform ; that they stained black with osmic 

 acid and red with alkanna. While, however, fat treated with 

 osmium was insoluble in choloroform and bergamot oil, the 

 blackened cortical granules proved to be soluble in these reagents 

 and in xylol. For these reasons, Rabl held that the cortical 

 granules, though not fat, were allied to it. These findings were 

 confirmed by M. Pfaundler in the case of the dog and the 



