776 MOVEMENTS OF THE SPLEEN. [BOOK n. 



special cells of the spleen. There are present, occasionally at least, 

 so-called giant cells, very large cells, each bearing not a single 

 nucleus but several nuclei, as if several cells were fused together 

 into one mass. More constant than these are cells smaller but 

 still large, twice as large as an ordinary white corpuscle or it may 

 be even larger than this, which contain in their cell-substance 

 numerous refractive, pale yellow or colourless granules. Some of 

 these forms, which like the others exhibit amoeboid movements, 

 and are often irregular in shape, are characterized by the presence 

 in their cell -substance of red corpuscles, sometimes in almost a 

 natural condition, sometimes more or less irregular in shape with 

 their red haemoglobin changing into the browner haBmatin, and 

 sometimes disintegrated into a mass of brown granules. The fluid 

 or plasma in which these cells float also contains besides normal 

 red corpuscles a certain number of red corpuscles in various stages 

 of change, as well as pigment granules which appear to be derived 

 from haemoglobin. Obviously a certain number of red corpuscles 

 do undergo change in the spleen, but whether the change is mainly 

 effected in the cell-substance of the cells just mentioned, or takes 

 place in the plasma, the products of disintegration being sub- 

 sequently taken up, in amoeboid fashion, by the cells in question is 

 not as yet clear. These cells appear to ingest not only red blood 

 corpuscles but also other bodies ; bacilli or other micro-organisms 

 are found lodged in their cell-substance in cases of disease caused 

 by such organisms. This is notably the case with the bacillus 

 anthracis (in splenic fever). Besides the above cells, in the spleen 

 of young animals, nucleated cells with hemoglobin holding 

 cell-substance, hsematoblasts (see 27), have been described ; these 

 are said to appear also in the spleen of adults after very great loss 

 of blood. 



475. The Movements of the Spleen. As we have already 

 stated, the volume of the spleen is subject to considerable vari- 

 ations. 



After a meal the spleen increases in size, reaching its maximum 

 about five hours after the taking of food ; it remains swollen for 

 some time, and then returns to its normal bulk. In certain 

 diseases, such as in the pyrexia attendant on certain fevers or 

 inflammations, and more especially in ague, a somewhat similar 

 temporary enlargement takes place. In prolonged ague a per- 

 manent hypertrophy of the spleen, the so-called ague-cake, 

 occurs. 



The turgescence of the spleen seems to be due to a relaxation 

 both of the small arteries and of the muscular tissue of the capsule 

 and of the trabeculae ; to be, in fact, a vascular dilation accom- 

 panied by a local inhibition of the tonic contraction of the other 

 plain muscular fibres entering into the structure of the organ, the 

 latter, at all events in some animals, being probably the more 

 important of the two. And the condition of the spleen, like that 



