200 C.-E. A. WiNSLOw AND Anne F. Rogers 



were relieved of such vast and unwieldy and meaningless genera 

 as now burden the science. 



The first of these groups centers about a type of organism char- 

 acterized by the following properties: it is parasitic in habit and 

 grows in irregular groups, often in chains, never in packets; it stains 

 by Gram; it grows in a thin film on the surface of agar; it ferments 

 both lactose and dextrose with the production of a large amount of 

 acid; it fails to reduce nitrates or hquefy gelatin, grows best at 37°, 

 and forms no appreciable amount of pigm.ent. This corresponds 

 to the genus Streptococcus (Billroth) W. and R., as previously char- 

 acterized. We desire to add to our previous conception of the group 

 the positive reaction to the Gram stain and the general failure to 

 act on gelatin or nitrates. It must always be remembered that this 

 genus is defined, not on morphology alone, although its members 

 generally do show long chains in broth, but by the general complex 

 of all its characters. Individual cultures vary from the type in 

 some respects, as must all aggregates of organisms composed of 

 such varying stuff as hving protoplasm. 



Of our 500 cultures 18 fall into the genus Streptococcus. All 

 show the typical morphology (groups and long and short chains) and 

 typical surface growth. None liquefy gelatin or reduce nitrates. Of 

 our 18 cultures, 15 were from the body and three from polluted water. 

 In relation to the Gram stain, 11 cultures showed positive tests, on 

 both trials, and only two a negative test, five being variable. Of 

 the 18 cultures, nine showed very high acidities, over 2 per cent 

 normal, in both acids, some ranging as high as 8 to 9 per cent. The 

 average value for the whole genus is, for dextrose 2.6 per cent, 

 and for lactose i . 7 per cent. It is interesting to notice that those 

 cultures which yield lower acidities are also the ones which give 

 the negative or variable Gram reactions. Our forms therefore seem 

 to fall into two species, 10 of them belonging to the Str. erysipelatos, 

 showing the very high acidities and the positive Gram reaction; 

 the other eight differing in both these characters. 



The second of our five groups is marked by a correlation of char- 

 acters, of which the most obvious is the production of an orange 

 pigment. In our previous communication we were unable to dis- 

 tinguish, from the literature alone, any sharp line between the orange 



