190 MICROBIOLOGY 



with those of Passet, 6 were of special influence in placing our 

 knowledge of the pathogenic properties of streptococci upon 

 & scientific basis. 



Gordon 7 pointed out that streptococci could be separated 

 into well defined groups by a study of their fermentative ac- 

 tion in various carbo-hydrate media. Andrews and Horder 8 

 founded a rational classification on the fermentation reactions 

 of the streptococci and in 1910 Winslow and Palmer 9 pointed 

 out certain differences in the intestinal streptococci of the 

 horse, cow and man. They showed that the streptococci from 

 man and horse fermented dextrose more or less vigorously, but 

 those from man produced more acid than those from the horse. 

 The streptococci from the bovine species exhibited two distinct 

 and clearly marked types, one forming a considerable amount 

 of acid approaching those from the horse, the other forming no 

 acid at all. Moore 1 studied 28 cultures of streptococci isolated 

 from tissues in the investigation of animal diseases. "When 

 compared on different media they were found to differ often 

 but slightly one from another. 



Classification of streptococci. A few investigators have 

 tried to eliminate the confusion concerning species by classi- 

 fying streptococci according to distinct morphologic charac- 

 ters and pathogenic properties. Of these classifications the 

 following may be mentioned : 



The classification of von Lingelsheim. 2 This author di- 

 vides all streptococci into two groups or species, namely : 



(a) Streptococcus brevis which is non-pathogenic. 



.(b) Streptococcus longus which is pathogenic. 



This is a combination of pathogenesis and morphology 



6 Passet. Untersuchungen liber die eitrigen Phlegm., u. s. w. 

 Berlin, 1885. 



7 Gordon. 33rd. Annual Kept, of Local Govt. Board, containing 

 report of the medical officer, p. 384-388. 



8 Andrews and Horder. Lancet, Vol. CLXXI (1906) p. 708. 

 'Winslow and Palmer. Journal of Infectious Diseases, Vol. VII 



<1910) p. 1. 



1 Moore. Bulletin No. 3, B. A. I., U. S. Dept Agric., 1893. 



2 Von Lingelsheim. Zeit. f. Hygiene, Bd. X (1891) p. 331. 



