On Certain Bacteria from the Air of Neiv York City. 351 



Biology. Gelatin is quickly li((uefied but in (2) pvoceeeded slowly and was 

 not complete. Milk is coagulated, forming a solid curd, but in { 2) only 

 so on boiling. Nitrate very slightly reduced; rosalic acid unchanged 

 GroA\i;h on solid media opaque white ; in broth, a white precipitate with 

 a slight growth at the svirface or on the side of the tube. Grows well 

 at 37^° C. 



Bemarls. I see no essential differences between the descriptions of 3ficrococcus 

 acidi ladici liquefaciens Kreuger, Micrococcus ureae liqnefaciens Fliigge, or 

 Sarcina alba Eisenberg, to either of which the present species might be re- 

 ferred. It does not ])elong to either of the si^ecies under the names of 

 which it was sent to me. 



19. Micrococcus flavus liquefaciens (Fliigge). 



Occurrence. In the air of an apartment house on West 69th St. 



Morphology. Large spherical Micrococci, 1-1.25 fi in diameter, singly, in pairs 

 or irregular groups. 



Biology. Liquefaction of the gelatin takes place very slowly. When first ob- 

 tained, it ensued in ten days, but proceeded very slowly. After the cul- 

 ture had been kept a year, liciuefaction was not obtained imtil the two 

 cultures which had been made had been growing twenty-eight and fifty 

 days respectively'. A very slight reduction of nitrate was ol)taiued in 

 twenty-eight days, none before that time. Growth on solid media, white 

 at first, later becoming pale yellow. Growth on glycerine agar and at 

 372° C. is white, but in the latter case the yellow color is regained on 

 being ti-ansferred to the room temperature. 



Bemarls. This differs a little from Fliigge's species with which I have identi- 

 fied it, but apparently only in liquefying gelatin more slowly and being 

 less chromogenic. No growth was obtained on potato. 



20. Micrococcus flavus desidens (Flugge). 



Occurrence. In the air of an apartment house on West 69th St. 



3Iorphology. Small Micrococci, .6-. 7// in diameter, in irregular groups. 



Biology. As indic<ated in the synopsis. The liquefaction of gelatin is very 

 slow and only appears in old cultures ( first seen in fifty -six days ) . A 

 partial reduction of nitrate is obtained in twenty-eight days. On solid 

 media the growth is lemon yellow, rather thin, poor on glycerine agar ; 

 on potato slight growth, yellowish, but the potato assumed a pink tint. 



Bemarks. It dift'ers from the species ^vith which I have identified it in liqui- 

 fying gelatin much more slowly. 



21. Merisniopedia fragilis n. sp. 



Occurrence. In the air on 59th St. 



Moi-pTiology. Micrococci 1-1.2 /^ in diameter, in twos, fours and irregular 

 groups but scarcely forming well defined packets. 



Biology. Gelatin liquefied rather slowly, but beginning in six days; characters 

 all negative except the reddening of lactose-litmus, and this is not of a 

 very pronounced character. Growth on agar poor, thin, translucent, pink- 



