374 On Certam Bacteria from the Air of Neio York City. 



only jiartially ; lactose-litmus made blue, rosolic acid not chanf;ed. 

 Growth on solid media soft, thick, yellow, with a pink tint in the 

 medium. 



105. BacilllliS Iielvoltis ( Zimmermann) . 



Occurrence. ( 1 ) From Krai's laboratory. ( 2 ) " Staphylococcus cereus flavus ' ' 

 from the college collection. (3) A contamination from the air of the col- 

 lej;e laboratory. (4) From the air of an apartment house on West <)!)th 

 Street. (5) From air of the college hallway. 



Slorphologij. As in No. 104, or the cells a little longer. 



Biolof/y. Gelatin slowly liquefied, sometimes not for thirty or forty days, but 

 the character is variable ; milk not coagulated ; nitrate not reduced, 

 slightly reduced, or even conqiletely reduced, but usually not for some 

 time. Growth on agar yellow with or without a pink tint in the medium. 



Bemiirlx. This form grades into the preceding. Zimmermann does not men- 

 tion the pink pigment and it was not visible in my cultures from Europe 

 at first, ))ut came out some three months afterwards. My measurements 

 are all shorter than tliose given in the books as the preparations were all 

 made from agar cultures. 



-*t>" 



106. Bacillus Iielvuliis graiiiilatus n. sp. 



Occurrence. Found in the process of imrifyiug a culture of No. 105. 

 3Torj)7i()Ioi/// and biology. As in No. 105, but the growth on agar is granular 

 lumpy, pale yellow, with scarcely any pink tint. 



107. Bacillus erytlirogeues rugatus n. sp. 



Occurrence. This is the "wrinkly form" of No. 104 with which the exjieri- 

 ments on discontinuous variations hereinbefore recounted were carried on. 



MorphnJoej!) and biology. It differs from No. 104 in that growth on agar is 

 thin, skinny and covered with coarse ^vrinkles. (See figure. ) 



Bemarks. This comes near B. plicatus Zimmermann, but liquefies gelatin 

 much more raj)idly, besides producing the pink color in media. 



108. Bacillus eta n. sp. 



Occurrence. In the air of the college hallway. 



Morpholoejy. Small rounded bacilli, .bY,.l-\ it, mostly singly; not motile. 



Biolofjjj. Gelatin liqiu'fied slowly (in twenty-eight to one hundred days), 

 milk not coagulated, nitrate completely reduced, but slowly; rosalic acid 

 not changed. On solid media, yellow, \iscous, with no x^ink tint. 



109. Bacillus fluorescens liquefaciens (Fliigge). 

 Occurrence. (1) From Krai's laboratory. (2) "Bacillus pyocyaneus " from 



the college collection. 

 3Iorphol(>rjy. Sliort rounded bacilli, .5X-'7-1.2 /', uu)stly singly, actively motile- 

 Bioloff//. Gelatin quickly liijuefied, milk not coagulated, but the casein is 



dissolved ; nitrate well reduced but not completely. Lactose-litmus not 



reddened ; rosolic acid decolored. 



