STUDT OF COVER-SLIPS AND SECTIONS. 225 



At the centre can be seen a dense, granular mass, which 

 stains readily with the basic aniline dyes and, when 

 highly magnified, is found to be made up of staphy- 

 lococci. Sometimes the shape of this mass of staphylo- 

 cocci corresponds to that of the capillary in which the 

 organisms became lodged and developed. Immediately 

 about the embolus of cocci the tissues are seen to be in 

 an advanced stage of necrosis. Their structure is 

 almost completely destroyed, though it is seen to be 

 more advanced in some of the elements of the tissues 

 than in others. As we approach the periphery of this 

 faintly stained necrotic area, it becomes marked here 

 and there with granular bodies, irregular in size and 

 shape, Avhich stain in the same way as do tlie nuclei of 

 the pus-cells and represent the result of disintegration 

 going on in these cells. 



Beyond this we come upon a dense, deeply stained 

 zone, consisting of closely packed pus-cells ; of granular 

 detritus resulting from destructive processes acting upon 

 these cells ; and of the normal cellular and connective- 

 tissue elements of the part. Here and there through 

 this zone will be seen localized areas of beginning death 

 of the tissues. This zone gradually fades away into the 

 healthy surrounding tissues. It constitutes the so-called 

 "abscess-wal\," 



Such is the picture presented by the miliary abscess 

 when produced experimentally in the rabbit, and it 

 corresponds throughout with the pathological changes 

 which accompany the formation of larger abscesses in 

 the tissues of human beings. 



From these small abscesses in the tissues of the rabbit 

 the staphylococcus pyogenes aureus may again be ob- 

 tained in pure culture, and will present identically the 



