STUDY OF COVER-SLIPS AND SECTIONS. 223 



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

 stains readily with the aniline dyes and, wheu highly 

 magnified, is found to be made up of staphylococci. Some- 

 times the shape of this mass of staphylococci 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 de- 

 stroyed, 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, which stain in the 

 same way as do the nuclei of the pus-cells and represent 

 the result of disintregation 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 wall." 



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 

 same characteristics that were possessed by the culture 

 with which the animal was inoculated. 



