67 



145 



son with our saprophytic streptococci, we liavo investigated, by the same methods, some 

 few pathogenic streptococci, kindly furnislied by Professor, Dr. C. (). .Iknsiïn, Dr. Wil- 

 helm Jensen and Dr. Oluf Thomsen. AU of them form dextro-lactic acid without any 

 considerable quantity of by-products. Nos. 1—9, which appear in all nutritive substrates 

 as shorter or longer chains, will, not stand heating beyond 60°, and thrive very poorly 

 below 15° and over 40°. Nos. 10 and 11, on the other hand, which in all nutritive substrates 

 appear chiefly as diplococci, are not killed until 75°, and grow well at temperatures from 

 12° to 50°. They are thus not affected even by the highest fever temperatures. Nos. 8 — 11 

 were not difficult to keep alive with the nutritive substrates eni|)l()ye(l, whereas most 

 of the other pathogenic streptococci died off in course of time. 



As regards the chain-forming strains, it would be natural to consider them related 

 to Sc. maslilidis, which forms the proper connecting link between the streptococci of milk 

 and the true pathogenic streptococci; they resemble this form also in growing particularly 

 badly in yeast extract. Some of them also ferment starch (without attacking raffinose 

 and inulin), which was, as we have seen, a particular characteristic in the freshly isolated 

 strains of Sc. mastiiidis. They form no colouring matter from it, however, and differ per- 

 ceptibly from Sc. maslilidis by growing poorly in milk; several of them, indeed, do not 

 ferment lactose at all. Like the other long-chained forms, Sc. maslilidis, Sc. cremoris, 

 Sc. tliermophihis and Sc. glycerinaceus No. 6, they do not ferment pentoses. The strains 

 which produce epizootic pneumonia, as well as petechial fever of the horse and navel and 

 joint evil of foals are distinguished by fermenting sorbite, without being able to attack 

 mannite, which is otherwise far easier to ferment. No. 8, and especially No. 9, are red in 

 the stab in casein peptone agar, a featui e which we have not observed in other lactic-acid 

 bacteria, but which is said to be cliaracteristic of Sc. lanceolalus and Sc. mucosus and 

 which is very common in the propionic acid bacteria. There can hardly be any doubt that 

 the present group contains several new species. In the table, we have shown the fermen- 

 tation figures for those of our saprophytic streptococci which most nearly resemble them. 

 The one isolated from sour cabbage is a long-chained streptococcus which does not grow 

 at temperatures over 40°. 



As regards Nos. 11 and 12 these should, from their appearance, their relation to 

 temperature, and their fermentation of sugars, simply be regarded as pathogenic strains 

 of Sc. fæcium. 



It follows then, that the name Slreplococcus pyogenes — like most of the bacteria 

 names hitherto employed is a collective term, embracing several species. Winslow^) 

 sets up no less than six species, three of which do not resemble any of our strains. 



With regard to Sc .lanceolalus, of which we have also investigated one or two strains, 

 and Sc. mucosus, these form no considerable quantity of lactic acid at all. Judging from 

 their shape, we may just as well reckon them among the micrococci, and Winslow also 

 places them in the genus Diplococcus, which comprises the most pathogenic micrococci. 



') Systematic Relationships of the Coccaceae. New York 1908. 



19* 



