PERIOSTITIS AND OSTEOMYELITIS 217 



'iiftttal. Occasionally ulcerative endocarditis is produced by the 

 simple intravenous injection of staphylococci aud streptococci into the 

 circulation, but this is a very rare occurrence. It often follows, however, 

 when tlie valves have heen previously injured. Orth and Wyssokowitsch 

 at a comparatively early date produced the condition by damaging the 

 aortic cusps hy a glass rod introduced through the carotid, and after- 

 wards injecting staphylococci into the circulation. Similar experiments 

 have since been repeated with streptococci, pneumococci, and other 

 organisms, with like result. Ribbert found that if a potato culture of 



PlO. ~>9. Section of a vegetation in ulcerative endocarditis showing 

 numerous staphylococci lying in the spaces. The lower portion is a 

 tia-nient in process of separation. 



Stained by Gram's method and Bismarck-brown, x 600. 



the staphylococcus aureus were rubbed down in salt solution so as to 

 form an emulsion, and then injected into the circulation, some minute 

 fragments became arrested at the attachment of the chordae tendinere and 

 produced an ulcerative endocarditis. 



Acute Suppurative Periostitis and Osteomyelitis. Special 

 mention is made of this condition on account of its comparative 

 frequency and gravity. The great majority of cases are caused 

 by the pyogenic cocci, of which one or two varieties may be 



