MICROCOCCUS AUREUS 331 



inject into the circulation of the rabbit through a vein of 

 the ear, or in any other way, from 0.1 to 0.3 c.c. of a bouillon 

 culture or watery suspension of a virulent variety of this 

 organism, a fatal pyemia always follows in from two and 

 one-half to three days. A few hours before death the animal 

 suffers frequently from severe convulsions. Now and then 

 excessive secretion of urine is noticed. The animal may 

 appear in moderately good condition until from eight to 

 ten hours before death. At the autopsy a typical picture 

 presents: the voluntary muscles are seen to be marked 

 here and there by yellow spots, which average the size of a 

 flaxseed, and are of about the same shape. They lie usu- 

 ally with their long axis running parallel to the muscle- 

 fibres. As the abdominal and thoracic cavities are opened 

 the diaphragm is often seen to be studded with them. 

 Frequently the pericardial sac is distended with a clear 

 gelatinous fluid, and almost constantly the. yellow points 

 are seen in the myocardium. The kidne\'s are rarely with- 

 out them ; here they appear on the surface as isolated 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 have a dry, cheesy, necrotic 

 centre, in which the micrococci are present in large numbers 



