THE ADRENAL BODIES 237 



dog, and others have found in blood taken from the adrenal 

 vein a considerable number of highly refractive granules. 



Carlier investigated the adrenal of a hedgehog, and described 

 in the medullary cells deeply staining granules of varying size. 

 These he found also in the lumina of the venous sinuses either 

 singly or in clumps, and states that they could be observed 

 in different stages of elimination from the cells. Stilling records 

 that in " hunger " frogs the medullary cells are vacuolated, 

 and take on the bichromate reaction in an irregular fashion. 

 In summer frogs there is a distinct reduction in the amount 

 of the medullary substance. 



Hultgren and Anderson give a description of characteristic 

 granules in the medullary cells and in the blood of the adrenal 

 vein. They believe that they observed the passage of these 

 through the endothelium of the bloodvessels. Some writers 

 have described sharply defined spaces between the medullary 

 cells, which are regarded as intercellular canals. These com- 

 municate with blood spaces, and sometimes it may be observed 

 that not only the medullary vessels, but also the lacunae and 

 the intercellular spaces are filled with fine, darkly staining 

 particles. 



Ciaccio describes pericellular canaliculi, which he considers 

 are intimately related to the processes of secretion, and specific 

 granules in the medullary cells, which are of two kinds : the 

 one having a special affinity for the salts of chromic acid the 

 chromaphil granules ; the other having a special affinity for 

 perchloride of iron. 



Recently Stoerk and v. Haberer have stated that the char- 

 acteristic granules of the protoplasm of the adrenal medulla 

 are not cast out into the lumina of the vessels, but they repre- 

 sent structural units which are possibly to be regarded as the 

 seats of chemical action whose products are to be looked upon 

 as the true secretory materials of the medullary cells, which 

 materials pass into the blood by some such process as diffusion. 

 The fluid secretory product is the true bearer of the chroma- 

 phil reaction of the medullary cells, the granules having the 

 reaction only in their secretory phase, when they are just 

 forming the chromaphil substance. The fluid secretion can 

 be recognized intracellularly (in both the protoplasm and the 

 nucleus), and extracellular ly (in admixture with the serum of 

 the capillary -and venous blood). Besides the typical fine gran- 



