682 NON-PATHOGENIC BACILLI. 



389. BACILLUS LIQUEFACIENS (Eisenberg). 



Found ill water. 



Morphology. Short, rather thick rods with round ends. 



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

 lus. Spore formation not observed. Grows rapidly at the room tempera- 

 ture not at 37 C. Upon gelatin plates forms round colonies with a 

 smooth margin, which in the middle are white and slimy ; liquefaction com- 

 mences in saucer shape and progresses rapidly; after a time a putrefactive 

 odor is given off. In gelatin stick cultures development is rapid and lique- 

 faction occurs in the form of a funnel, often like an air bubble; the line of 

 puncture is filled with a whitish, granular mass. Upon the surface of agar 

 forms a dirty-white layer. Upon potato a pale-yellow growth. 



390. BACILLUS MAIDIS (Cuboni). 



Obtained from corn which had been soaked in water for eight hours at 

 30 C., and in the faeces of individuals suffering from pellagra. 



Morphology. Bacilli with square ends, from 2 to 3 n long; solitary, in 

 pairs, or in chains of three elements seldom more ; resembles Bacillus me- 

 sentericus f uscus in morphological and biological characters. 



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

 lus. Forms large oval spores located at the centre of the rods. Grows in 

 the usual culture media at the room temperature best at 26 to 30 C. Pro- 

 duces in saccharine solutions acetic and butyric acids. Upon gelatin plates, 

 at the end of twenty-four to thirty-six hours, grayish-white, puiictiform col- 

 onies are developed below the surface, which have a yellowish color. The 

 superficial colonies are thin and veil-like ; under a low power they are seen 

 to be finely granular and have an irregularly folded margin ; later liquefac- 

 tion commences and they have a radiate, finely striped margin ; the lique- 

 faction progresses rapidly, forming shallow, saucer-like cavities. In gelatin 

 stick cultures liquefaction occurs along the line of puncture within twenty- 

 four hours in the form of a funnel or cylindrical tube, and rapidly extends 

 to the walls of the test tube at the surface. Upon the surface of agar, at 34 

 to 36 C., a thin, dry, wrinkled layer covers the entire surface within twen- 

 ty-four hours ; this is white or yellowish-white and easily detached. Upon 

 potato a white, somewhat granular, and later finely wrinkled layer, which 

 acquires a yellowish-brown color. Blood serum is liquefied by this bacillus. 



391. PROTEUS SULFUREUS (Lindenborn). 



Found in water. 



Morphology. Bacilli of various lengths, the average length being about 

 1.6 fJ- and the breadth 0.8 /*; often in long chains or filaments. Resembles 

 Proteus vulgaris, and is perhaps identical with this species (Eisenberg). 



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

 formation not observed. Grows rapidly at the room temperature. Forms 

 sulphuretted hydrogen. Upon gelatin plates forms white colonies, from 

 which filamentous outgrowths upon the surface of the gelatin are given off ; 

 these form "swimming islands"; later liquefaction occurs in the form of 

 broad funnels with grayish -white contents. In gelatin stick cultures devel- 

 opment occurs along the line of puncture, and liquefaction in funnel shape 

 near the surface. Upon the surface of agar a thick, grayish-white layer is 

 developed. Upon potato a slimy, grayish- white layer, which later acquires 

 a brownish color. In milk an alkaline reaction is produced in the course of 

 several weeks, and the casein is peptonized without previous precipitation ; 

 the milk acquires a bitter taste and a yellowish color. 



392. BACILLUS THERMOPHILUS (Miquel). 



Found in the contents of sewers, in the alimentary tract of man and ani- 

 mals, and in the soil. 



