STUDY OF COVER-SLIPS AND SECTIONS. 239 



appear on the surface, scattered about as single yellow 

 points, or again, are seen as conglomerate masses of 

 small yellow points which occupy, as a rule, the area 

 fed by a single vessel. If one make a section into one 

 of these yellow points it will be seen to extend deep 

 down through the substance of the kidney as a yellow, 

 wedge-shaped mass, the base of the wedge being at the 

 surface of the organ. 



It is very rare that these abscesses for abscesses the 

 yellow points are, as we shall see when we come to 

 study them more closely are found either in the liver, 

 spleen, or brain ; their usual location being, as said, in 

 the kidney, myocardium, and voluntary muscles. 



These minute abscesses contain a dry, cheesy, necrotic 

 centre, in which the staphylococci are present in large 

 numbers, as may be seen upon cover-slips prepared from 

 them. They may also be obtained in pure culture from 

 these suppurating foci. 



Preserve in Miiller's fluid and in alcohol duplicate 

 bits of all the tissue in which the abscesses are located. 



When these tissues are hard enough to cut, sections 

 should be made through the abscess-points, and the his- 

 tological changes carefully studied. 



MICROSCOPIC STUDY OF COVER- SLIPS AND SECTIONS. 

 In cover-slip preparations this organism stains readily 

 with the ordinary dyes. 



In tissues, however, it is best to employ some method 

 by means of which contrast stains may be employed, 

 and the location and grouping of the organisms in the 

 tissues rendered more conspicuous. 



When stained, sections of tissues containing these 

 small abscesses present the following appearances : 



To the naked eye will be seen here and there in the 



