THE SUPRARENAL BODIES. 737 



of the stomach and duodenum, in connection with certain changes in 

 the circulation, dependent on digestion. , The small size of the spleen 

 during that process, is attributed to the bloodvessels of the stomach 

 and duodenum, being at that period distended ; whilst, when digestion 

 is completed, those vessels diminish in size, and the spleen enlarges. 

 The spleen is certainly quickly reduced in size, when the portal venous 

 system is unloaded by hemorrhage or by purgatives, and it becomes 

 enlarged in obstructive diseases of the liver and heart ; but the idea 

 of its serving specially as a diverticulum, is too mechanical, and but 

 partially expresses its true function. A mere plexus of bloodvessels 

 would have sufficed for such a purpose, without the co-operation of a 

 peculiar parenchyma, like the splenic pulp ; moreover, as already 

 stated, not merely are the bloodvessels of the spleen distended during 

 its periodic enlargement, but the splenic pulp itself, and even the little 

 Malpighian bodies, are obviously increased in volume. 



Notwithstanding much that is obscure in the history of this organ, 

 it would seem, from the abundance and character of its microscopic 

 elements, its chemical composition, its large supply of bloodvessels, 

 and the peculiar relation of these to the pulp, that the spleen probably 

 has for its office, as an assimilative or nutritive gland, the elaboration 

 of the albuminoid constituents of the blood, and perhaps, as Hewson 

 long ago suggested, the formation, like the lymphatic glands, of the 

 germs of the white and red blood-corpuscles. The supposition that it is 

 also the seat of a degeneration of the red corpuscles, is no contradiction 

 to such a view. Some of the materials of the old corpuscles, as, e. g., 

 the pigment, may be used up again in the formation of new ones ; for, 

 like all ductless glands, the spleen, whilst, on the one hand, it abstracts 

 materials from the blood, by special nutritive processes, on the other, 

 it returns to that fluid, in some altered condition, all that it has so 

 attracted from it. 



The suprarenal bodies or capsules. These organs, two in number, 

 one on each side of the body, are small, flat, triangular, yellowish 

 masses, placed on the summit of the corresponding kidneys, which 

 they surmount like a cocked hat. Each measures about 1J inch in 

 width and 2 or 3 lines in thickness, and weighs nearly 2 drachms. 

 They consist of an outer deep-yellow, firm, cortical portion, and of an 

 inner dark, soft, medullary part, the whole organ being invested by a 

 proper areolar coat, which sends prolongations into its interior. The 

 cortical part presents numerous oval loculi, or spaces, in the areolar 

 framework, placed end to end in little rows or columns, and arranged 

 perpendicularly to the surface. These loculi were formerly thought to 

 be oval or tubular closed vesicles, with distinct walls ; but they are 

 merely interspaces in the areolar framework of the organ. They con- 

 tain a granular plasma, composed of an abundance of granules, with 

 few or many fat particles, nuclei, and nucleated cells ; towards the 

 centre of the organ, the cells are larger and less regularly arranged, 

 so that the columnar appearance is there lost. The medullary, or 

 softer central portion, is composed of a delicate filamentous tissue, con- 

 nected with the areolar tunic and framework of the cortical substance, 

 and having in its interspaces also, besides bloodvessels, a granular 



47 



