690 



NON-PATHOGENIC BACILLI. 



oxygen, at the room temperature. Upon cigar plates, in the absence of air, 

 small, yellowish-white colonies are developed which are irregular in form 

 and vary considerably in size; these are surrounded by outgrowths which 

 are more compact and less branched than similar colonies of the bacillus of 

 malignant oedema. In nutrient gelatin irregular, spherical colonies are de- 

 veloped, which rapidly cause liquefaction of the surrounding gelatin, and 

 spherical cavities filled with a deeply clouded liquid are formed. In blood 

 serum a homogeneous cloudiness is seen in the vicinity of the line of punc- 

 ture, and at the lower part of this a few isolated, irregularly branching col- 

 onies are developed. A considerable amount of gas is formed in the cultures 

 in various media ; this appears as scattered bubbles, and also causes a split- 

 ting-up of the culture medium ; in gelatin cultures liquefaction gradually 

 extends upward until it reaches the surface. The gases evolved have an ex- 

 tremely disagreeable odor; they are produced more abundantly in culture 

 media containing sugar. 



406. BACILLUS LIQUEFACIENS MAGNUS (Luderitz). 



Found in garden earth by inoculations in mice and guinea-pigs. 

 Morphology. Bacilli with slightly rounded ends, straight or slightly 

 curved, from 3 to 6 u long and from 0.8 to 1.1 /z thick; may grow out into 

 long, flexible filaments. 



Biological Characters. A a anaerobic, lique- 

 fying, motile bacillus. Grows rapidly at the 

 room temperature, in the absence of oxygen, in 

 the usual culture media. Forms long-oval 

 spores, from 1 to 2 /* long and 0.8 n broad; 

 these are located at or near the middle of bacilli 

 from 4 to 6 /* long not in the long fila- 

 ments unless these are segmented. When culti- 

 vated in a medium containing grape sugar, the 

 spore-bearing bacilli are stained violet with 

 iodine solution sometimes pale and in places 

 only, at others throughout. In gelatin cultures 

 development is already evident, at the end of 

 twenty -four hours, one or two centimetres below 

 the surface, as scattered punctiform colonies ; at 

 the end of two days these are one to two milli- 

 metres in diameter and have smooth margins, 

 with transparent, dull-white contents; at the 

 end of three or four days the gelatin is usually 

 entirely liquefied ; the liquefaction extends upward, and the liquefied gela- 

 tin, which at first is clouded, becomes clear, while a slimy, whitish deposit 

 is seen at the bottom of the tube. In cultures containing grape sugar some 

 gas is developed ; this has a disagreeable odor like that of old cheese. In 

 gelatin stick cultures liquefaction begins along the line of puncture, from 

 1 to 1.5 centimetres below the surface, within forty-eight hours; and a sau- 

 sage- shaped collection of liquefied gelatin, of a dull-white, or silver-gray color, 

 is seen. In long agar cultures development is rapid, and colonies are seen 

 nearer the surface than in similar gelatin cultures often within five milli- 

 metres; the young colonies have a delicately branched, moss-like appear- 

 ance; in older colonies the branching is coarser. In stick cultures in blood 

 serum, in the incubating oven, at the end of twenty four hours a simple 

 line of growth is seen along the lower portion of the track of the inoculat- 

 ing needle ; later numerous lateral offshoots give the growth a brush-like 

 appearance; the blood serum is soon liquefied and foul-smelling gases are 

 given off. Not pathogenic for mice or for guinea-pigs. 



407. BACILLUS LIQUEFACIENS PARVUS (Luderitz). 

 Obtained from garden earth by inoculations in mice and guinea-pigs. 



FIG. 232. Bacillus liquefa- 

 ciens magnus ; young colonies in 

 nutrient gelatin, x 60. (Lude- 

 ritz.) 



