THE SUPRARENAL CAPSULES OR ADRENAL BODIES. 347 



peculiar cells, the concentric corpuscles of Hassal (Fig. 189), 

 which consist of a central cell around which flattened epithelial 

 cells are arranged concentrically. 



The arteries which supply this gland are derived from the 

 internal mammary and the 

 superior and inferior thyroid. 

 The nerves are from the pneu- 

 mogastric and sympathetic. 



Function. T o g e t h e r 

 with other glands containing 

 lymphoid tissue, the thymus 

 is undoubtedly a source of 

 leukocytes; and because < 

 Watney has found in cells of 

 the thymus hemoglobin vary- 

 ing in shape from granules to 

 masses having the appearance 



of red blood-corpuscles, and FIG. 189. Hassal's corpuscle and a small 



^milir pplk in the Ivnmh P ortiori of medullary substance, showing 



V III P 11 reticulum and cells, from thymus of a child 



corning from the gland, he ten days old (Huber). 



concludes that the thymus is 



one of the sources of red blood-corpuscles. So far as known, no 



effects are produced by injecting into the tissue an extract of the 



thymus, nor by injecting portions of the gland itself. 



THE SUPRARENAL CAPSULES OR ADRENAL BODIES. 



These are flattened, glandular structures situated one above and 

 one in front of the upper part of each kidney. In length each 

 is about 3.5 cm., in width 2.5 cm., and in thickness 1 cm., the 

 right being smaller than the left. They present a cocked-hat 

 appearance. The weight of each is about 4 grams. 



Chemical Composition. These bodies contain proteids, 

 cell-globulin and nucleoproteid, extractives such as occur in the 

 other ductless glands, salts, of which one is potassium phos- 

 phate, hippuric and taurocholic acids. The presence of a reducing 

 substance similar to jecorin of the liver has been claimed by some, 

 but denied by others. 



Structure. There is a marked difference between the struct- 

 ure of the suprarenal capsules and the other ductless glands which 

 we have considered. Each capsule is invested with a fibrous cap- 

 side. On section (Fig. 190) it is found to consist of a cortical portion 

 or cortex, the greater part of the gland, which is yellow in color 

 and presents a striated appearance ; and a medullary portion or 

 medulla, which is of a dark-brown or dark-red color. The capsule 

 gives off septa, which so divide the cortex as to leave spaces, filled 

 with granular, polyhedral cells, some of them containing oil- 



