182 IMFLAMMATION AND SUPPURATION 



organism also may vary, and corresponding results may be pro- 

 duced. Especially is this so in the case of the streptococcus 

 pyogenes. 



The staphylococcus aureus, when injected subcutaneously in 

 suitable numbers, produces an acute local inflammation, which 

 is followed by suppuration, in the manner described above. 

 The spread of the suppuration goes pari passu with the growth 

 of the cocci. If a large dose is injected the cocci may enter the 

 blood stream in sufficient numbers to cause secondary suppurative 

 foci in internal organs (cf. intravenous injection). 



Intravenous injection in rabbits, for example, produces interest- 

 ing results which vary according to the quantity used. If a con- 

 siderable quantity be injected, the animal may die in twenty-four 

 hours of a general septicaemia, numerous cocci being present in 

 the capillaries of the various organs, often forming plugs. If a 

 smaller quantity be used, the cocci gradually disappear from the 

 circulating blood ; some become destroyed, while others settle in 

 the capillary walls in various parts and produce minute abscesses. 

 These are most common in the kidneys, where they occur both 

 in the cortex and medulla as minute yellowish areas surrounded 

 by a zone of intense congestion and haemorrhage. Similar small 

 abscesses may be produced in the heart w r all, in the liver, under 

 the periosteum, and in- the interior of bones, and occasionally in 

 the striped muscles. Very rarely indeed, in experimental 

 injection, do the cocci settle on the healthy valves of the heart. 

 If, however, when the organisms are injected into the blood, 

 there be any traumatism of a valve, or of any other part of the 

 body, they show a special tendency to settle at these weakened 

 points. 



Experiments on the human subject have also proved the 

 pyogenic properties of those organisms. Garre inoculated 

 scratches near the root of his finger-nail with a pure culture, a 

 small cutaneous pustule resulting ; and by rubbing a culture over 

 the skin of the forearm he caused a carbuncular condition which 

 healed only after some weeks. Confirmatory experiments of 

 this nature have been made by Bockhart, Bumm, and others. 



When tested experimentally the staphylococcus pyogenes albus 

 has practically the same pathogenic effects as the staphylococcus 

 aureus. 



The streptococcus pyogenes is an organism the virulence of 

 which varies much according to the diseased condition from which 

 it has been obtained, and also one which loses its virulence 

 rapidly in cultures. Even highly virulent cultures, if grown 

 under ordinary conditions, in the course of time lose practically all 



