THE SPLEEN. 



187 



blood. Some observations suggest the conclusion that the cause of 

 splenic enlargement is the destruction of red corpuscles (or possibly 

 leucocytes also), haemolysis, which is frequent and pronounced in 

 many infectious diseases. This is notably the case in malaria, in 

 which the red corpuscles are destroyed by the plasmodium occasion- 

 ing the disease. When bacteria gain access to the blood, they are 

 apt to be especially abundant in the splenic pulp, and it is said that 

 monkeys, which are normally immune against relapsing fever, 

 may acquire the disease if the spleen be removed before inoculation 



Fig. 161. 



Section from human spleen. (Kolliker.) A, capsule ; 6, 6, trabecule ; c, c, Malpighian bodies 

 (lymph-follicles), traversed by arterial twigs. In the follicle to the left, part of the 

 arterial twig is seen in longitudinal section ; in that to the right, it appears in cross- 

 section to the right of the centre of the follicle, rf, arterial branches; e, splenic pulp. 

 The section is taken from an injected spleen. 



with the spirillum which is the cause of that disease. Removal of 

 the spleen leads to a diminution of the number of red corpuscles in 

 the peripheral circulation and to a still greater diminution in the 

 haemoglobin of the blood, which lasts for many weeks, but eventually 

 normal conditions are usually re-established, perhaps because of 

 changes in the red marrow of the bones. These observations all 

 tend to confirm the view that the function of the spleen is to assist 

 in maintaining the functional integrity of the blood. The lymph- 

 adenoid tissue within the spleen also enriches the blood with an addi- 

 tional number of leucocytes. 



