420 THE DUCTLESS GLANDS. 



There is reason to believe, too, that in the spleen many 

 of the red corpuscles of the blood, those probably which 

 have discharged their office and are worn out, undergo 

 disintegration ; for in the coloured portion of the spleen- 

 pulp an abundance of such corpuscles, in various stages of 

 degeneration, are found, while the red corpuscles in the 

 splenic venous blood are said to be relatively diminished. 

 According to Kolliker's description of this process of disin- 

 tegration, the blood-corpuscles, becoming smaller and 

 darker, collect together in roundish heaps, which may 

 remain in this condition, or become each surrounded by a 

 cell-wall. The cells thus produced may contain from one 

 to twenty blood-corpuscles in their interior. These cor- 

 puscles become smaller and smaller ; exchange their red 

 for a golden-yellow, brown, or black colour ; and, at length, 

 are converted into pigment-granules, which by degrees 

 become paler and paler, until all colour is lost. The 

 corpuscles undergo these changes whether the heaps of 

 them are enveloped by a cell- wall or not. 



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 con- 

 cluded, it is supposed 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 undergoes in certain affections of the heart and liver, 

 attended with obstruction to the passage of blood through 

 the latter organ, and by its diminution when the congestion 

 of the portal system is relieved by discharges from the 

 bowels, or by the effusion of blood into the stomach. 

 This mechanical influence on the circulation, however, 

 can hardly be supposed to be more than a very subordinate 



