viii] MICROCOCCI J47 



and death, with plugging of capillaries in the parenchyma- 

 tous viscera with masses of streptococci, are observed ; the 

 blood yields on culture numerous colonies of streptococci. 



Streptococci resembling in morphological and cultural 

 respects the streptococcus pyogenes are found in connected 

 masses in the ulcerated tissue and on the villous out- 

 growths of the cardiac valves in some forms of ulcerative 

 endocarditis. In other cases of ulcerative endocarditis 

 masses of staphylococcus aureus only occur. Also in puer- 

 peral septicaemia a streptococcus is cultivable from the blood 

 and spleen which in cultural respects resembles the strepto- 

 coccus pyogenes except that it is more virulent, producing on 

 injection into the subcutaneous tissue of the rabbit's ear an 

 extensive blush and occasionally acute septicaemic infection. 

 It is difficult to say whether this streptococcus is a virulent 

 variety of streptococcus pyogenes or a less virulent variety 

 of the streptococcus erysipelatos. 



It is an easily ascertained fact that the streptococcus pyo- 

 genes cultivated from phlegmon and various purulent exuda- 

 tions when tested on the animal (notably the rabbit's ear) 

 does not behave in a uniform manner, inasmuch as in some 

 instances it acts virulently, causing distinct and spreading 

 blush and purulent exudation and even general infection, 

 whereas in others it has no appreciable pathogenic action 

 under the same conditions ; and it is likewise a fact that a 

 streptococcus, which is pathogenic at first, by repeated sub- 

 culture loses this action. 



5. Streptococcus erysipelatos. — Fehleisen first isolated this 

 microbe from the progressing margin of erysipelas ; it is 

 a microbe which, as sections through the erysipelatous 

 skin show, is abundantly present in the distended lymph- 

 spaces and lymph-vessels of the marginal part. The mor- 

 phological and cultural characters coincide with that of the 



