NON-PATHOGENIC BACILLI. 647 



Biological Characters. An aerobic and facultative anaerobic, non- 

 liquefying, motile bacillus. Spore formation not observed. Gi*ows rapidly 

 at the room temperature not so well in the incubating oven. Growth 

 occurs at a temperature as low as 5 to 7 C. Upon gelatin plates, at the 

 end of two days, the superficial colonies are seen as flat discs with a thicker 

 and whitish centre and very thin, bluish, notched margins ; under a low 

 power the surface is seen to becovered with fine lines or furrows which cross 

 each other at various angles; the color is white, with a yellowish tint at the 

 centre ; later very numerous lines are seen crossing each other in all direc- 

 tions at the centre, while the periphery is still white and is marked by more 

 delicate lines. The deep colonies are round and yellowish. In gelatin stick 

 cultures a flat, white layer with notched edges is seen at the end of twenty- 

 four hours ; this becomes thicker and is of less diameter than the surface 

 growth of the typhoid bacillus under similar conditions. Upon the surface 

 of agar, at 37. 5 C., a tolerably thick, white layer is developed; this has an 

 odor like that of milk. Upon potato, at 37.5 C., the growth is invisible, 

 the line of inoculation having only a moist appearance ; at the room tem- 

 perature this is also the case at first, but later a very thin, moist-shining, 

 of ten cream-colored layer with raised edges is seen, and the potato around 

 this acquires a bluish-gray color, which again fades out. 



306. BACILLUS AQUATILIS SULCATUS NO. ii. (Weichselbaum). 



Found in the Vienna water supply. 



Morphology. Short bacilli with round ends, of the form and dimensions 

 of the shorter typhoid bacilli. 



Biological Characters. An aerobic an d facultative anaerobic, non-lique- 

 fying, motile bacillus. Spore formation not observed. Grows in the usual 

 culture media at the room temperature not so well in the incubating oven. 

 Grows at a lower temperature than the typhoid bacillus 5 to 7 C. Upon 

 gelatin plates, at the end of two days, the superficial colonies are similar to 

 those of the typhoid bacillus and of the preceding species, but somewhat 

 thicker and not visibly notched ; under the microscope they are seen to be in- 

 distinctly notched and marked by lines, although not so distinctly as are the 

 colonies of Bacillus aquatilis sulcatus No. I. ; the centre of the disc-shaped 

 colonies is yellowish, the periphery white; after three days they become 

 thicker and* the notching of the margins and lines upon the surface are no 

 longer seen, while the entire colony, with the exception of the outer margin, 

 has a yellowish color. In gelatin stick cultures a whitish, rather thick 

 layer of limited dimensions is formed upon the surface. Upon the surface 

 of agar, in the incubator, a grayish- white layer is developed in twenty -four 

 hours. Upon potato, at the room temperatui'e, a bluish-gray color is first 

 seen along the line of inoculation, and a yellowish- gray or yellowish-brown 

 layer is subsequently developed ; this may become tolerably abundant, while 

 the original color disappears ; potato cultures give off a slight uriiious odor. 



307. BACILLUS AQUATILIS SULCATUS NO. in. (Weichselbaum). 



Found in the Vienna water supply. 



Morphology. Very short bacilli, frequently resembling micrococci. 



Biological Characters. An aerobic and facultative anaerobic, non- 

 liquefying, motile bacillus. Spore formation not observed. Grows at the 

 room temperature and at 5 to 7 3 C. not so well in the incubating oven. Old 

 cultures give off a disagreeable odor. Upon gelatin plates, at the end of 

 two or three days, the superficial colonies are disc-shaped, with a thicker, 

 white centre and a very thin, bluish periphery; the margin is notched; 

 under the microscope the surface is seen to be marked with lines; later the 

 colonies increase in thickness and diameter and lose the bluish color ; the 

 system of fine lines also disappears, and the surface is covered with numerous 

 short lines and furrows; the yellow color extends from the centre nearer to 



