272 INTERNAL SECRETION 



glomerulosa is absent altogether. The form of the cortical cells 

 is polygonal in man only; in the greater number of mammals the 

 cells of the outer zone are long, narrow and cylindrical in shape. 

 The most perfect cortical cylinders are observed in the horse and 

 the dog. In microscopic sections taken from these animals the 

 cell strands appear as perfect rings which closely resemble tubular 

 glands. Whether or no the cortical cell groups enclose a lumen 

 is a question of the utmost importance to both pathological and 

 physiological histology, and one which has recently been sub- 

 jected to searching investigation by Stoerk. He showed that, 

 under normal conditions, there is no free space within the loop- 

 like arrangement of cell cylinders, although the appearance of 

 these sometimes closely simulates a lumen formation. Where, 

 for instance, owing to the over-tilling of the suprarenal vessels, 

 there is extravasation of blood into the external cortical layer, the 

 cell columns become detached from the connective tissue by which 

 the vessels are conveyed; thus, appearances are produced which, 

 where the extravascular blood is not demonstrable as such, bear 

 a misleading resemblance to transverse and oblique sections from 

 glands. This effect is heightened by the fact that compression 

 of the cell contents produces an apparently basal position of the 

 nuclei. From the nature of his findings, Stoerk is convinced that 

 the suprarenal cortex does not assume the formation of a true 

 gland under either normal or pathological conditions (hyper- 

 trophy, adenoma). 



The most important structural characteristic of the cortical 

 cells is supplied by the lipoid granules which they contain ; these 

 resemble fat granules and are usually known as the cortical 

 granules. The chemical nature of these granules will be described 

 later; their histological characteristics are, briefly, as follows :- 



If the cortex of a fresh mammalian suprarenal is teased out 

 in physiological saline solution, the result will be a granular mass 

 containing, in addition to single perfect polygonal cells filled with 

 granules, an enormous number of free spheroids. These are pale 

 yellowish in colour, very bright, double refractive, and i to 4 

 microns in size. Occasionally, these spheroids run together to 

 form, in some cases, largish drops, in others, what are known 

 as myelin forms. The large drop formation is very well seen after 

 the addition of glacial acetic acid, concentrated mineral acids, or 

 33 per cent, liquor potassa? solution ; though, when diluted, the 

 same acids and potash solution produce no change. The cortical 

 granules are soluble in fat solvents (ether, chloroform, xylol, 

 alcohol, though more slowly by the latter), and the addition of 

 water to these solutions produces the same globular formations. 

 The cortical granules do not stain with either fuchsin, methylene 

 blue, or other similar colouring agents ; but they stain vividly with 

 the specific stains for fat (alkanna, sudan III, scarlet R) ; and in 

 perosmic acid they colour a profound black. If, after colouring 



