322 HANDBOOK OF PHYSIOLOGY. 



this material, seem to indicate that this organ is concerned in storing up 

 some of the changed and absorbed proteid food, to be gradually intro- 

 duced into the blood according to the demands of the general system. 



(2.) It seems probable that the spleen, like the lymphatic glands, is 

 engaged in the formation of Uood-corpusdes. For it is quite certain 

 that the blood of the splenic vein contains an unusually large amount of 

 white corpuscles; and in the disease termed leucocythaemia, in which 

 the pale corpuscles of the blood are remarkably increased in number, 

 there is almost always found an hypertrophied state of the spleen or of 

 the lymphatic glands. In Kolliker's opinion, the development of color- 

 less and also colored corpuscles of the blood is one of the essential func- 

 tions of the spleen, into the veins of which the new-formed corpuscles 

 pass, and are thus conveyed into the general current of the circulation. 



(3.) The formation of red corpuscles. The spleen is concerned in the 

 formation of red corpuscles during foetal life and shortly after birth, and 

 in some animals during their whole existence. For, if the spleen be 

 removed from such animals, the red marrow undergoes hypertrophy. 

 Moreover, in these animals the cells previously described as ha3matoblasts 

 may be found in the spleen. 



It was formerly believed that the spleen exercised the function of de- 

 stroying red corpuscles that had lived out their allotted time. The evi- 

 dence of this, however, is not convincing, and the theory has been 

 practically abandoned. It rested chiefly upon the fact that large nu- 

 cleated cells were found in the spleen, with whole or partially disinte- 

 grated red cells in their interior. But the phenomenon is probably of 

 post-mortem occurrence. When the circulation ceases, the red cells 

 come to rest, and, lying alongside these large cells, are probably then 

 ingested. 



(4.) From the almost constant presence of uric acid, in larger quan- 

 tities than in other organs, as well as of the nitrogenous bodies, xanthin, 

 hypoxanthin, and leucin, in the spleen, some special nitrogenous meta- 

 bolism may be fairly inferred to occur in it. One of the features of the 

 chemical composition of the spleen is the presence of a special proteid, 

 of the nature of alkali-albumin, containing iron. The salts of the 

 spleen consist chiefly of sodium phosphates. 



(5.) Besides these, its supposed direct offices, the spleen is believed to 

 fulfil some purpose in regard to the portal circulation, with which it is 

 in close connection. From the readiness with which it admits of being 

 distended, and from the fact that it is generally small while gastric 

 digestion is going on, and enlarges when that act is concluded, it is sup- 

 posed to act as a kind of vascular reservoir, or diverticulum to the portal 

 system, or more particularly to the vessels of the stomach. That it may 

 serve such a purpose is also made probable by the enlargement which it 



