STREPTOCOCCI 151 



genes types with the former predominating (vide p. 155). 

 The bovine type Str. mastiditis, and the human type Str. 

 anginosus he was imable to distinguish either morphologically 

 or biochemically, but a marked difference in virulence was 

 found on animal injection. By auto inoculation on the tonsils 

 Savage was unable to produce either local or general symptoms 

 with Str. mastiditis even when massive doses were employed, 

 and, in general, the organisms could only be recovered with 

 difficulty even after such a short period as two to three days. 

 The author has been unable to find any record of any tests being 

 made by Savage as to the haemolytic properties of the organisms 

 isolated by him; this is of considerable importance, as haemolysis 

 is now generally regarded as characteristic of the pathogenic 

 types Str. pyogenes and Str. anginosus. 



Until 1911 septic sore throat seems to have been passed 

 unrecognised in America, but the Boston epidemic in that year, 

 with over 2000 cases, gave an impetus to the study of this disease, 

 and since then it has proved to be one of the most fertile fields 

 for research work. In the Boston epidemic, as in the later ones 

 at Chicago, Baltimore, Concord (N. H.) and other places, the 

 origin was traced to the milk supply and it was circumstantially 

 established that the specific cause was a haemolytic strepto- 

 coccus of the pyogenes variety. 



Krumwiede and Valentine^ investigated an outbreak of 

 septic sore throat on Long Island in 1914 and reported that it 

 was caused by the transfer of pathogenic streptococci from a 

 case of sore throat on a farm to one of the cows in the herd. An 

 examination of the herd showed that five cows were giving milk 

 containing a moderate number of streptococci from one or more 

 quarters and that one of these gave physical evidence of mas- 

 titis. All these streptococci, however, were non-haemolytic, 

 but one other cow was found in which were moderate numbers 

 of haemolytic streptococci in two quarters and enormous num- 

 bers in a third quarter. The milk from this quarter was floc- 

 culent. These streptococci were morphologically and bio- 

 chemically identical with those isolated from the throats of the 



