DESCRIPTION OF SPECIES 



447 



Biology : cultural characters {includ- 

 ing biochemical features). 



Bouillon — Turbidity and surface 

 membrane after 3 days ; occasional 

 chromogenicity. Abundant m 

 glycerine bouillon, yellow mem- 

 brane. No indol. 



Gelatine plates and tubes — Slow, 

 poor growth ; small colonies. No 

 liquefaction. No gas production. 



Agar plates and tubes — Rapid, 

 abundant growth in 36 to 48 hours, 

 yellow or white, wrinkled ; re- 

 sembles tubercle bacillus ; yellow 

 colour may turn to orange. Grows 

 best in glycerine-agar ; translucent, 

 irregular surface. 



Potato — Thick, dry, yellow 

 growth, very adherent to the 

 medium. 



Milk — Slow (5th day) ; small 

 masses of growth, yellow ; some- 

 times a yellow pellicle on the 

 surface. No coagulation. 



Blood serum — Numerous small 

 colonies, remaining isolated and 

 discrete ; uncoloured. 



Aerobic — Slow, feeble growth 

 anaerobically. 



Pathogenesis — Moeller found this 

 bacillus when injected intraperi- 

 toneally killed guinea-pigs in 2 or 

 3 days, and the bacillus was isolated 

 from the blood. In other cases, 

 nodules were found on mesenteries, 

 etc. (similar to Rabinowitsch's 

 butter bacillus). Its effects most 

 marked on guinea-pigs. 



TORUIiA AMARA (Harrison). 



Source and habitat— Isolated from 

 milk-can washings, and maple 

 leaves at Guelph, Canada. Pro- 

 duced a marked bitterness in 

 milk. 



Morphology — Oval cells, varying size, 

 7-5 to lo-o /i long ; after some 



days' growth vacuolation occurs 

 in the cells. Budding occurs at 

 the smaller end of the cell. Cells 

 appear singly, or in small clumps 

 or short chains. No spores. 

 Wort — At 25° C, abundant growth. 

 No pellicle ; yeast rings occur in 

 same medium at 37° C. 



Wort gelatine — (20° C.) pin - point 

 colonies ; in 4 days become round 

 greyish-white, shining. 



Gelatine — Like wort gelatine. In 

 stab-cultures, beaded line of punc- 

 ture, which in 20 to 30 days be- 

 comes dense, spiny growth, radiat- 

 ing from beads. Surface growth 

 waxy, greyish - white, becoming 

 brown at centre. 



Wort agar — Rapid luxuriant growth 

 at 37' C. 



Agar — Glistening, flat growth in 8 

 days at 25° C. 



Potato — Slightly raised growth in 3 

 days at 20° C, at 37° C. slightly 

 yellower colour. 



Milk — Bitter taste produced in 5 or 

 6 hours at 37° C. In 10 days milk 

 is thickened, slightly acid, and 

 very bitter. There is much gas 

 formed. No butyric acid is 

 present. 



Non-pathogenic. 



TYKOTHBIX CATENUIjA (Duclaux). 



Source and habitat — Cheese. 



Morphology — Bacillus, -6 m broad by 

 3 to 5 /x long. Grown in the 

 absence of ox>'gen, the elements 

 are short and thick ; grown aerobi- 

 cally, they are thicker and of greater 

 length. Isolated or in chains. 



Motility — Actively motile when iso- 

 lated ; slow movement when in 

 chains. 



Sp>ore formation — Mesial spores, volu- 

 minous, oval, and longer than the 

 primitive elements. 



