BACTERIA, NOT CLASSIFIED. 719 



Biological Characters. A. strictly anaerobic, non-liquefying, motile 

 bacillus. Forms spores. Grows in the usual culture media in ail atmo- 

 sphere of hydrogen at the room temperature. In nutrient gelatin colonies 

 are developed at the end of five or six days ; these are small, white plaques 

 surrounded by gas bubbles. Upon potato, in an atmosphere of hydrogen, 

 whitish colonies are developed, around which the potato appears excavated; 

 at the same time it is partly liquefied by the ferment action of the bacillus,' 

 and the liquid collects at the bottom of the tube. When these potato tubes 

 are opened there is a little explosion, due to escaping gas. The development 

 of the bacillus is most rapid and its ferment action most energetic at a tem- 

 perature of about 35 C It causes fermentation of sugar and of starch, but 

 not of cellulose. It ceases to grow in cultures containing 0.10 to 0.12 per 

 cent of acid (estimated in sulphuric acid), and, as it produces an acid reac- 

 tion of the culture medium, it is necessary to add carbonate of lime to this 

 to insure its continuous development. The acids formed from the fermenta- 

 tion of sugar are acetic (at the outset) and butyric. In culture media con- 

 taining starch, ethylic and amylic alcohol are produced, as well as butyric 

 acid ; a considerable portion of the starch is converted into sugar, and hydro- 

 gen and carbon dioxide are given off freely as a result of the fermentation. 



455. BACILLUS RUBELLUS (Okada). 



Obtained by Okada (1892) from dust by inoculations in guinea-pigs. Not 

 pathogenic, but found in association with pathogenic bacteria in the bloody 

 serum effused about the point of inoculation with dust from the streets. 



Morphology. Resembles Bacillus cedematis maligni in its form and di- 

 mensions. Bacilli with slightly rounded ends, usually in pairs or chains of 

 three; in old bouillon cultures grows out into filaments 10 to 15 // long; 

 these are often surrounded by a capsule-like envelope. The rods show a 

 slight swelling when spore formation occurs, becoming spindle shaped or 

 having an expanded extremity, according as the spore is formed in the 

 middle or at one extremity. Flagella may be demonstrated by Loffler's 

 method of staining; these are seen at one or at both extremities. 



Stains with the usual aniline colors and also by Gram's method. 



Biological Characters. An anaerobic, chromogenic, liquefying, motile 

 bacillus. Forms large oval spoi-es, which are located at one extremity or in 

 the centre of the rods. In gelatin plates kept in an atmosphere of hydro- 

 gen, dull-white, punctiform colonies are developed at the end of ten days at 

 15 to 18 C ; under a low power these are seen to be long-oval in form and 

 surrounded by fine offshoots ; after a time the gelatin is liquefied and ac- 

 quires a reddish color. In deep gelatin stick cultures development com- 

 mences at the bottom of the line of puncture, where, at the end of ten days, 

 small, dull-white, spherical or oval colonies are developed ; these are seen to 

 be surrounded by radiating offshoots ; the colonies increase in size, and the 

 gelatin is gradually liquefied in the lower two-thirds of the tube, while 

 above it remains solid ; a flocculent deposit is now seen at the bottom of the 

 tube, which has a reddish color; finally the upper portion of the gelatin is 

 also liquefied and the whole of the fluid has a red color. Upon agar plates, 

 at 37 C. , development is more abundant and rapid ; colonies are developed in 

 twenty-four hours, which subsequently increase in size and acquire a red 

 color. In deep stick cultures in agar, in the incubating oven, development 

 occurs below at the end of twenty-four hours and gradually extends up- 

 ward to near the surface. Gradually the upper portion of the growth ac- 

 quires a red color, which increases in intensity, and the upper portion of the 

 culture medium is after a time diffusely colored. In bouillon in an atmo- 

 sphere of hydrogen, at 37 C. , development is abundant and rapid, and the 

 medium acquires a red color. 



Not pathogenic. 



