216 



INFLAMMATION AND SUPPUKATION 



Endocarditis. — There is now strong evidence that all cases of 

 acute endocarditis are due to bacterial infection. In the simple 

 or vegetative form, so often the result of acute rheumatism, the 

 micrococcus rheumaticus (p. 221) has been cultivated from the 

 valves in a certain number of cases, and is probably the causal 

 agent in most instances. 



Endocarditis of the ulcerative type may be produced by 



Fig. 53. — Section of a vegetation in ulcerative endocarditis showing 

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

 fragment in process of separation. 



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



various organisms, chiefly pyogenic. Of these the streptococci 

 and staphylococci are most frequently found; the former pro- 

 ducing less destructive changes, the formation of abundant 

 vegetations being not uncommon. In the case of streptococcic 

 infection we meet with all degrees of severity, and in view of the 

 bacteriological results rheumatic endocarditis is probably to be 

 regarded merely as the mildest example. In some cases of 

 ulcerative endocarditis following pneumonia the pneumococcus 

 (FraenkeFs) is present ; in these the vegetations often reach a 



