THE SUPRARENAL GLANDS 447 



glomerulosa inward to the zona reticularis. The cells are colum- 

 nar or polyhedral in shape ; many of them contain minute fatty 

 droplets in great abundance. This fat is readily blackened by os- 

 mic acid. Arnold,* by extraction with ether, obtained crystals of 

 palmatin and stearin from the suprarenal gland. Plecnik,f how- 

 ever, considers that the adrenal fat differs in its ultimate chemical 

 properties from the other fat of the body. Each columnar group 

 consists of cells which are, as a rule, in approximately the same 

 stage of fatty metamorphosis, and the cell columns of this zone 

 may be divided into those which are distinctly acidophile and 

 those which are distinctly fatty, though between these extremes 

 there are many intermediate stages. 



The acidophile cells are ovoid or polyhedral elements which 

 possess one or two highly chromatic spheroidal nuclei and a finely 

 granular cytoplasm. On careful examination with high magnifi- 

 cation, extremely minute fat droplets may often be demonstrated 

 even in the most characteristic of these cells ; with lower magnifi- 

 cation these are frequently invisible. 



The fatty cells possess a spheroidal nucleus which is usually 

 vesicular in character ; occasionally it is highly chromatic. Fre- 

 quently the apparent chromatolysis seems to progress in exact ratio 

 to the accumulation of fat ; those cells in which the fatty meta- 

 morphosis is more advanced present the more typically vesicular 

 nucleus. With the progress of the fatty metamorphosis the cell 

 outlines are again lost and the granular acidophile cytoplasm 

 gradually replaced. The presence of fat in the broad zona fas- 

 ciculata is partially responsible for the bright yellow color of the 

 cortex of the organ. 



The cells of the zona reticularis are similar to those of the zona 

 fasciculata, though the fatty metamorphosis is less pronounced. 

 In one particular, however, the cells of this layer are remarkable. 

 They contain an abundance of a peculiar brownish-yellow pigment 

 which occurs both in the form of coarse granules and as a diffuse 

 coloration of the cytoplasm. The spherical nuclei, highly chro- 

 matic or only slightly vesicular in character, are not invaded by 

 the pigmentation. The volume of pigment varies greatly in differ- 

 ent individuals ; it is usually absent in young persons, but is, as a 

 rule, present after the twentieth year of life (Maass J). 



The epithelial cells of the medulla are ovoid elements with one 

 or two spherical nuclei, which in many cases possess a vesicular 



* Loc. cit. f Arch. f. mik. Anat., 1902. \ Arch. f. mik. Anat, 1889. 



