

CHAP, xxxv.] USES OF THE SPLEEN. 517 



twenty experiments, was blood expelled from the organ, or its 

 diameter diminished. Not only does the spleen perform this phy- 

 sical office, but, as has been shown, certain important chemical and 

 microscopical changes are found to have occurred in the blood 

 which has passed through this organ. In 1847, Kolliker advanced 

 the theory that blood corpuscles became disintegrated in the 

 spleen, an opinion which was afterwards supported by Ecker and 

 Beclard. From various facts which we have alluded to, we cannot 

 but look upon this point as decided in the affirmative, although 

 others have been led to adopt the view, that blood corpuscles are 

 actually formed, instead of being disintegrated, in this organ. 

 Kolliker thought that the colouring matter of the blood was 

 changed in the spleen, and converted into the peculiar colouring 

 matter of the bile ; but Mr. Gray has shown, that yellowish-green 

 bile is found in the gall-bladder of the chick, at a period consider- 

 ably antecedent to the development of the splenic vein. The 

 small size of the spleen in the foetus, as compared with its increase 

 after birth, and in adult life, renders it improbable that in intra- 

 uterine life it acts the part either of a blood-forming, or blood- 

 destroying, organ. 



Its great increase in size, in well-fed animals, and its diminu- 

 tion in insufficiently-fed animals, and, especially its increase after 

 the completion of digestion, render it extremely probable that it 

 has the power of storing up albuminous material for future con- 

 sumption, when a larger quantity of nutrient material is taken 

 than is required for the immediate wants of the system. The cells 

 of the Malpighian corpuscles appear, from Mr. Gray's observations, 

 to be the organs especially concerned in this process. 



Supra-renal Capsules. The supra-renal capsules are two bodies 

 of a somewhat triangular form, situated one on each side of the 

 spine, a little above the corresponding kidney, to the capsule of 

 which each is connected by loose cellular tissue. 



Each supra-renal capsule is about an inch and a half in depth, 

 somewhat less in width, and usually about half an inch in thick- 

 ness. The weight varies from one to two drachms. The gland is 

 enclosed in a thin fibrous capsule, which dips down into its sub- 

 stance. It is surrounded with loose areolar tissue, containing an 

 abundant quantity of fat. 



Upon making a section through the body, it is found to be com- 

 posed of two distinct portions, a cortical and a medullary part. 

 The former is of a yellowish colour, shading into a brown border 

 towards the interior. It tears somewhat readily, and then exhibits 



