SPLEEN. 369 



there scattered through the organ (Malpighian corpuscles) ; and 

 (2) the peculiar soft splenic pulp. 



The small, rounded masses of lymph follicular tissue are 

 situated on the course of the fine arterial twigs. The delicate 

 adenoid reticulum which holds the lymph cells together is inti- 

 mately connected with the vessel wall. The pale appearance of 

 these follicles, which distinguishes them from the surrounding 

 splenic pulp, depends on the number of the white cells which 

 are packed in the meshes of this perivascular adenoid tissue. 



The splenic pulp consists of a system of communicating lacunar 

 spaces lined with endothelium. Into these spaces the blood is 

 poured from the arteries, and thus mingles with vast numbers 



FIG. 161. 



(a) Trabeculse of the Spleen. (6) Artery cut obliquely. (Cadiat.) 



of white cells. Besides the ordinary blood disks and the white 

 corpuscles or lymph cells, many peculiar cells are found in the 

 spleen pulp. Some of these look like lymph cells containing 

 little masses of hemoglobin, and appear to be transitions from 

 the colorless to the red corpuscles, while others, small, misshapen, 

 red corpuscles, are regarded as steps in a retrograde change in 

 the disks. But few, if any, lymph channels lead from the spleen 

 pulp, and only a relatively small number pass out from the hilus, 

 so that the splenic artery and vein must be regarded as taking 

 the place of the afferent and efferent lymph channels. 



Chemical examination shows the splenic pulp to have remark- 



