THE SPLEEN. 151 



Anat./ II, 2; and Todd's 'Cyclopaedia of Anatomy and Phy- 

 siology/ Art. Spleen, fig. 533; Ecker, ' Icon. Phys./ tab. vi, 

 figs. 15, 16); 2. extravasations and metamorphoses of their 

 blood-corpuscles occur, not only in the spleen, but in other 

 organs, especially in the kidneys, where they are constant, and 

 frequently also in the liver and peritoneum. 



If to these facts we also add, that in certain animals, e. g. 

 the Cat, the Sheep, &c, the changes of the blood-corpuscles in 

 the spleen are very rarely met with — furthermore, that their 

 progress is not always coincident with the stages of digestion 

 — it becomes very difficult not to believe that the phenomena 

 are abnormal, especially if we consider that similar phenomena 

 certainly not physiological, such as the small effusions of 

 blood into the lungs, bronchial glands and thyroid in Man, in 

 the lymphatic glands of the mesentery of the Pig and Rabbit, 

 &c, are also, on the one hand, almost as constant phenomena, 

 and, on the other hand, are accompanied by perfectly similar 

 metamorphoses of the blood-corpuscles. However, in the 

 latter cases, the quantity of the metamorphosed blood-cor- 

 puscles is not to be compared to the immense number of those 

 which are constantly undergoing disintegration in the spleen ; 

 and in the second place, it is also possible that effusion of 

 blood may occur as a physiological phenomenon, as into the 

 Graaffian follicles, and during menstruation and the detachment 

 of the placenta. And although all animals do not present a 

 microscopically demonstrable disintegration of the blood-cor- 

 puscles in their spleen, yet it does not follow that the process 

 may not occur and that when it can actually be demonstrated, 

 it is pathological. This much is at least certain, that conges- 

 tions of blood in the spleen occur in all animals, without ex- 

 ception ; and it is almost certain, that these congestions are, in 

 Mammals, attended by extravasation. In these stagnations of 

 blood, the blood-corpuscles may be disintegrated, in some cases 

 rapidly, in others slowly, which would constitute an important 

 difference for the observer ; it is also conceivable that they and 

 their consequences are physiological and have some great in- 

 fluence upon life, since it is a fact, that in many animals they 

 are constant, and occur upon a very large scale. 



For the present, therefore, so long as the pathological 

 character of the phenomena in question is not conclusively 



