3G8 On Certain Bacteria from the Air of New York City. 



aerobic and forms a thick compact surface skin on liqnid media. On agar 

 the gTOwth is liroad, translucent ocheroiis yenoA\', concentrically marked. 

 It comes oft' in pieces under the needle and is difficult to transfer. 



77. Bacillus rulJidiis (Eisenberg). 



Occurrence. ( 1 ) As a contamination. ( 2 ) Tliree times in the air of the college 

 yard near 59th street. (3) In a trap of the carnivorous water plaiit 

 Utricuhiria vulgaris in Dead Creek, Plattsburgh, N. Y. 



Morphology. Small rounded bacilli .5-.7X-6-1 ,", singly or in short chains, not 

 motile except No. (3) which A\as motile when fresh Init not in older cul- 

 tures. 



Biology. Gelatin quickly liquefied, but in No. (1) not for seventy days and 

 then only a dry hollow was found. Milk not coagulated iisually, but in 

 a culture of No. (3) there Avas coagulation or boiling in fourteen days, 

 but not subsequeuth'. In another of No. (3) there was a partial pastry co- 

 agulum in twenty-eight days on boiling. Nitrate not reduced or very 

 slightly. Tlie gro\\i;h on agar varies in color, but is of a translucent red- 

 dish brown shading into yellowish, oi-ange or Avhitish. 



Eemarl:!<. Tliese cultures are not all alike, as \\\\\ be noticed, and do not coitc- 

 spond entirely with Eisenberg' s description, but I have preferred to re- 

 gard them as varieties of one species. 



78. Bacillus delta n. sp. 



Occurrence. From a water plate. 



Morpliology. Short bacilli, .5X-8-1//, singly and in short chains, not motile. 



Biology. Gelatin slo\vly li(jiiefied, beginning in twenty-one days. IMilk not 

 coagiilated on boiling, though it may appear somewhat so before. Eosolic 

 acid not changed. On agar the growth is so thin that its red color is 

 scarcely apparent, but it is CA^ident on milk at the surface. Grows well 

 at 372°C, of a translucent light pink. On potato shining, light red, not 

 greatly spreading. 



79. Bacillus fiilvus (Zimmermann). 



Occurrence. (1) In the air of the college hallway. (2) In the air of an apart- 

 ment house on West 69th street. (3) From a water plate. 



Morpliology and biology. Under the above name, I associate three cultures 

 which agree in liquefying gelatin very slo\\ ly, usually not for twenty-one 

 days. Lactose-litmus reddened, rosolic acid not changed, no sirrface 

 growth on broth. Tliey differ as follows: (1) .5X.7-1/'; indol formed 

 abundantly; on potato a narrow rather shining bright yellow growth; 

 lactose-litmus permanently reddened. (2) 1X1-2 z^; scarcely any indol 

 formed ; no gro^v-th on potato ; lactose-litmus permanently reddened. ( 3 ) 

 .4X-5 // ; considerable indol is formed; on potato a coarse densely granular 

 dry growth, brown centrally, yellow on the edges; lactose-litmus made 

 red, but later becomes blue. 



Eemarkn. I am unable to decide whether these are distinct species or varieties 



