648 NON-PATHOGENIC BACILLI. 



the periphery. In gelatin stick cultures, at the end of twenty-four hours, a 

 very thin, white layer with notched edges is developed ; this extends rapidly 

 to the margins of the tube. Upon the surface of agar an abundant grayish- 

 white layer is quickly developed in the culture oven ; this has an odor re- 

 sembling that of milk. Upon potato, at the room temperature, a discolora- 

 tion of the line of inoculation is seen at the end of twenty -four hours ; later 

 an abundant pale-yellow layer with raised margins is developed which has 

 an odor of herring brine; at the end of nine days the potato around the 

 growth has a bluish-green color. 



308. BACILLUS AQUATILIS SULCATUS NO. iv. (Weichselbaum). 



Found in the Vienna water supply. 



Morphology. Bacilli of various lengths; often grow out into filaments. 



Biological Characters. An aerobic and facultative anaerobic, non- 

 liquefying, tnotile (the short rods only) bacillus. Spore formation not 

 demonstrated. Grows slowly at the room temperature still more so in the 

 incubating oven. Upon gelatin plates the colonies are first visible on the 

 fourth day; the superficial colonies are thin, bluish discs with notched mar- 

 gins and a somewhat thicker, whitish centre; under a low power the surface 

 is seen to be covered with fine lines, and the larger colonies have a yellowish 

 color in the centre ; later they increase in thickness and diameter and acquire 

 a yellow color throughout, while the system of lines is replaced by more 

 numerous and shorter lines and furrows. In gelatin stick cultures develop- 

 ment is very slow, but at the end of several days a grayish- white layer with 

 notched margins is developed, which gradually extends to the walls of the 

 test tube. Upon the surface of agar, at 37 C., the growth is very scanty at 

 the end of six days ; at the room temperature a grayish- white layer of mode- 

 rate thickness is formed within two days. Upon potato no growth occurs 

 either in the incubator or at the room temperature. 



309. BACILLUS AQUATILIS SULCATUS NO. V. (Weichselbaum). 



Found in the Vienna water supply. 



Morphology. Bacilli with round or pointed ends, of various lengths; 

 somewhat thicker than the typhoid bacillus. 



Biological Characters. An aerobic and facultative anaerobic, non- 

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

 room temperature in the usual culture media not in the incubating oven. 

 Upon gelatin plates forms colonies resembling those of Bacillus aquatilis 

 sulcatus No. I. , which become visible in two or three days. In gelatin stick 

 cultures a layer of moderate thickness is formed, which gradually extends 

 over the surface ; this is grayish- white at first and later has a yellow color 

 like that of the yolk of an egg. Upon the surface of agar no growth occurs 

 in the incubator, but at the room temperature an abundant, viscid, yellow- 

 ish layer is developed. Upon potato, at the room temperature, a bluish-yel- 

 low layer is formed and the potato around it acquires a dark-gray color, 

 which disappears later, while the vegetation after a time has a honey -yellow 

 color. 



310. BACILLUS MULTIPEDICULUS (Flugge). 



Found in the air and in water. 



Morphology. Long : slender bacilli. 



Biological Characters. An aerobic, non-liquefying, non-motile bacil- 

 lus. Spore formation not observed. Grows at the room temperature in the 

 usual culture media. Upon gelatin plates forms spherical or oval opaque 

 colonies, which under a low power are seen to give off at certain points of 

 the periphery broad, segmented outgrowths consisting of round zoogloea 



