280 DE A. J. WHITING ON THE 



In the pulp of the adult spleen there are four kinds of cells : — (1) Lymphoid cells, 

 which measure from 4-5 fi, stain deeply with hematoxylin, and resemble the cells of 

 the outer zone of the follicles. (2) Protoplasmic corpuscles, measuring 6-8 jjl with 

 usually a single, round, deeply stained nucleus, which is surrounded by a narrow or broad 

 rim of hyaline protoplasm. (3) Coarsely granular or eosinophilous cells occur in small 

 numbers, and vary in size correspondingly with the protoplasmic corpuscles. The largest 

 are oval, and their very coarse granules obscure the nucleus if such is present. (4) 

 Pigment-holding cells are in some spleens exceedingly numerous, in others quite sparse. 

 They are usually oval in shape and measure from about 15 /a to 20 /x longitudinally by 

 about 12 (jl in breadth. The pigment grains are of a yellow colour, and are of irregular 

 size and shape ; they are surrounded by a cell wall, but there is apparently no protoplasm 

 between them. An oval, blue-stained nucleus is sometimes to be seen about the middle 

 of the cell. The cells tend to adhere firmly to the reticulum. 



In the splenic pulp of the Young Pig, aged three months, similar cellular elements 

 are to be found, except pigment-holding cells, and there are in addition giant cells. 

 (Plate II. figs. 10 and 11.) 



The giant cells vary considerably in size, but their average measurement is about 

 30 /x in length and 18 /x in breadth. They are not by any means numerous : on an 

 average about sixty are present in each section.* Their characteristic shape is oval. 

 Their substance is a coarsely granular protoplasm, which stains of a deep pink colour 

 with eosine, and which in the unstained condition is of a yellow colour. They have 

 usually several nuclei, oval or round in shape, which are frequently connected together 

 by threads of nuclear substance, but more often they appear to be isolated. Some of 

 the smaller giant cells have only one large nucleus. The isolated nuclei of the 

 multinucleated forms are sometimes near the middle of the cell, but usually near 

 its periphery ; their average size is 5-8 ft. Near the margin of many of the giant 

 cells are rounded vacuoles, in size a little larger than the nuclei ; in some that are 

 situated quite close to the periphery of the cell there may be seen a deeply stained 

 nucleus. Sometimes there is a mouth-like opening at the margin of the cell, which 

 is probably the result of the rupture of a vacuole, and occasionally a vacuole is seen 

 to be connected with the surface by a somewhat narrow channel, thus forming a 

 pyriform space. 



Clustered near the margin of the giant cells, usually at points corresponding with 

 the mouth-like openings, are cells that have the character of erythroblasts. Their 

 usual measurement is 9-10 /x in diameter. They are round or oval in shape, and 

 consist of a deeply blue-stained, round nucleus, that has a well-marked intranuclear 

 network, but no nucleolus, which is surrounded by a rim of hyaline protoplasm, which 

 stains deeply with eosine, and is of a yellow colour when unstained. The nuclei arc 



* By the term " section " in this relation is meant a section through the entire spleen at its thickest part in its 

 transverse axis. In giving the number of giant cells in a section in the different spleens, my aim is to afford a basis for 

 a rough comparison between the spleens. Each section contains only a portion of each of the giant cells enumerated. 



