222 BACTERIOLOGY. 



These points, when in the kidney, may be round or oval 

 in outline, or may appear wedge-shaped, with the base 

 of the wedge toward the surface of the organ. The 

 differences in shape depend frequently upon the direction 

 in which the section has been made through the kidney. 

 In the muscles they are irregularly round or oval. 



When quite small they app?ar to the naked eye as 

 simple, round or oval, darkly stained points, but when 

 they are more advanced a pale centre can usually be 

 made out. 



When magnified, they appear in the earliest stages 

 as minute aggregations of small cells, the nuclei of 

 which stain intensely. Almost always there can be 

 seen about the centre of these cell-accumulations evi- 

 dences of progressing necrosis. The normal structure 

 of the cells of the tissue will be more or less destroyed ; 

 there will be seen a granular condition due to cell-frag- 

 mentation; at different points about the centre of this 

 area the tissue will appear cloudy and the tissue-cells 

 will not stain readily. All about and through this spot 

 will be seen the nuclei of pus cells, many of which are 

 undergoing disintegration. In the smallest of these 

 beginning abscesses the staphylococci are to be seen 

 scattered here and there about the centre of the necrotic 

 tissue, but in a more advanced stage they are commonly 

 seen massed together in very large numbers in the form 

 commonly referred to as emboli of micrococci. 



The localized necrosis of the tissues which is seen at 

 the centre of the abscess is the direct result of the 

 action of a poison produced by the bacteria, and is the 

 starting-point for all abscess- formations. 



When the process is somewhat advanced the different 

 parts of the abscess are more easily detected. They then 

 present in sections somewhat the following conditions : 



