364 APPLICATION OF METHODS OF BACTERIOLOGY 



cocci, but by many, the idea being that one or the other 

 of the component streptococci used in the process of immun- 

 ization may be identical, or sufficiently nearly so, to the one 

 concerned in the infection to be treated, as to play its part 

 in the production of the desired specific component of the 

 antiserum so obtained. This shot-gun-like proceedure some- 

 times succeeds, but even so, the element of uncertainty is 

 too evident to justify the adherence to it as a permanent 

 method. All the indications point to the substitution of a 

 more scientific, a more logical procedure in the near future, 

 a procedure closely allied to that by which the pneumo- 

 cocci have been grouped and from which so much light 

 has been shed upon the complicated problem of pneumonia. 



Though the last word has not yet been said, the indi- 

 cations are that in erysipelas, septic sore-throat, pleurisy, 

 rheumatism, scarlet fever anginas, measles sore-throat, 

 postinfluenzal pneumonia, wound infections, etc., we have 

 streptococci fundamentally different from the ubiquitous 

 Streptococcus pyogenes as commonly described. 



Not any of the many investigations of this phase of the 

 subject appear to illustrate more clearly the possibilities 

 and practical value of studies upon the streptococci than 

 do those of Havens, conducted in U. S. Gen. Hospital No. 

 12, at Biltmore, N. C. 1 



Havens undertook to classify the hemolytic streptococci 

 only, as there is now a general agreement that the non- 

 hemolytic varieties are of but subordinate importance 

 insofar as they concern infections in man. 



As material for his studies 292 different strains of strepto- 

 cocci were used; that is to say, there were that number of 



1 Jour. Infect. Dis., 1919, No. 4, vol. xxv. 



