DIGESTIVE ORGANS AND THEIR ANATOMY. 303 



of an outer cortical region, of a deep yellow color, consisting 

 of rods of cells and an inner medullary portion of a more 

 blackish color and quite soft and pulpy. 



A closer examination of this gland reveals that the cor- 

 tex consists of a framework of connective tissue, in which 

 are imbedded column-like groups of cells. In these col- 

 umns of cells there is, however, no lumen visible, so that 

 they are evidently not like the tubular glands found else- 

 where. The medullary portion consists of a much looser 

 framework of connective tissue, richly supplied with capil- 

 laries, while distributed through the interstices of this 

 framework there are groups of cells which resemble some- 

 what those found in the cortex. The function of these 

 structures, like that of the thyroid and spleen, is still in 

 doubt. The removal of these bodies is rapidly followed by 

 death. The symptoms which follow such removal are great 

 muscular weakness and relaxation of most of the blood-ves- 

 sels, and a general prostration. Similar symptoms occur 

 in a disease in man known as Addison's disease, which 

 clinical evidence has referred to pathological conditions of 

 the adrenal bodies. This disease is especially marked by 

 the appearance of bronzed patches on the skin, and so the 

 view has arisen that possibly these supra-renal bodies are 

 concerned in the elimination of an injurious pigment from 

 the blood, which, when it accumulates, produces the gen- 

 eral poisonous effects, and finally, if sufficiently concentrated, 

 discolors the skin to a deep bronze. On the other hand, 

 some observations seem to indicate that this gland does not 

 remove an injurious pigment from the blood, but that it 

 adds some beneficial substance which, when removed, leads 

 to the described results. Aqueous extracts of the adrenal 

 bodies have been made and injected into the blood-vessels 

 of living animals with the result that it affected in a remark- 

 able way the action of the heart, the blood-vessels, and even 

 the voluntary muscles. It made the contractions of the 

 heart more prolonged, strongly contracted the blood-vessels, 

 and so produced a great increase in blood pressure and pro- 



