NON-PATHOGENIC BACILLI. 077 



Upon the surface of cigar a white layer is formed. Upon potato a light- 

 brown, circular layer is quickly developed; this at first has a dull and later 

 a shining surface. 



377. BACILLUS INFLATUS (A. Koch). 



Found as an accidental impurity from the air ? 



Morphology. Bacilli from 4.6 to 5,5 /* long and 0.6 to 0.8 // broad; often 

 grow out into filaments. 



Biological Characters. An aerobic, liquefying, actively motile bacillus. 

 Forms two large spores in each rod. Grows at the room temperature. Upon 

 gelatin plates forms spherical white colonies with folded margins, from 

 which an outgrowth of delicate filaments is seen, similar to Bacillus alvei. 

 In gelatin stick cultures development occurs all along the line of puncture, 

 and short, hair-like filaments radiate into the gelatin, which is very slowly 

 liquefied. Upon the surface of agar forms a thin, slimy, light-brown 

 layer. In bouillon a thin, slimy, whitish film forms upon the surface, 

 which sinks to the bottom when the tube is shaken. 



378. BACILLUS RAMOSUS. 



Synonym. "Wurtzel bacillus. 



Found in the soil and in water common. 



Morphology. Bacilli with round ends, about three times as long as 

 broad "about as long as Bacillus subtilis, but thicker " (Frankel) ; fre- 

 quently united in long chains, or may grow out into filaments. 



Biological Characters. Anaerobic, liquefy ing bacillus. Exhibits slight 

 movements. Forms large oval spores which are located at the centre of 

 the rods. Grows rapidly at the room temperature also in the incubating 

 oven. Upon gelatin plates, at the end of two days, veil-like, rapidly ex- 

 tending, whitish colonies with ill-defined margins are developed; these re- 

 semble the mycelium of a fungus ; under a low power the colonies are seen 

 to consist of a network of twisted and interwoven filaments ; liquefaction oc- 

 curs in the course of a few days. In gelatin stick cultures an outgrowth of 

 branching filaments occurs along the line of puncture, looking ' ' like a 

 sma 1 ! fir tree turned upside down "; upon the surface a moist and shining, 

 white layer is developed ; liquefaction soon occurs at the surface, and pro- 

 gresses until the gelatin is entirely liquefied ; in old cultures a mycoderma 

 is seen upon the surface, the gelatin below this is transparent, and at the 

 bottom there is a deposit of crumbling, whitish flocculi. Upon the surface 

 of agar a development of branching filaments occurs along the line of in- 

 oculation; these form a moist- looking, grayish- white layer, which later be- 

 comes thicker at the centre, and the root-like growth is only seen at the 

 edges. Upon potato a whitish, smeary streak is developed along the line of 

 inoculation ; the bacilli form numerous large oval spores when cultivated 

 on potato. 



379. BACILLUS SUBTILIS (Ehrenberg). 



Synonym. Hay bacillus. 



A widely distributed species; found in hay infusion, in water, in the 

 soil, etc. 



Morphology. Bacilli with slightly rounded corners, from 4. 5 to 6 n long, 

 and about three times as long as broad ; usually in chains consisting of 

 several elements ; often grows out into very long filaments; possesses a ter- 

 minal flagellum at each end of a single rod or at the two extremities of a 

 chain. 



Biological Characters. An aerobic, liquefying, motile bacillus. Forms 

 large oval spores, which are located at the centre of the rods; these are 

 about 1.2 long and 0.6 n broad. The movements are of a waddling charac- 

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