4o6 DESCRIPTION OF SOME SPECIES OF MILK BACTERIA 



2, except upon agar. Those upon 

 this latter medium are well de- 

 veloped at the end of 24 hours, and 

 about the seventh day appear a 

 few granulations of a pale rose 

 colour ; and about the eighteenth 

 day the culture is found to be dry, 

 thin, lightly wrinkled, and of a pale 

 rose colour. At the end of 2 

 months the culture is of the same 

 aspect, and there is but little exuber- 

 ant growth. 



Pathogenic properties — Inocu- 

 lated into guinea-pigs, either intra- 

 peritoneally or subcutaneously, the 

 animal dies in from 10 days to a fort- 

 night with general congestion and 

 local lesions, from which pure 

 cultures of the organism can be 

 obtained upon glycerine-agar after 

 incubation for 7 or 8 days. The 

 colonies are of greyish-rose colour, 

 shining, and of fatty appearance, 

 and will be found to be constituted 

 of bacilli strongly resistant to 

 acids. 



BUTTER BACILLUS, No. 5 (Tobler). 

 Source and habitat — Zurich butter. 



Morphology — The bacilli, which ordin- 

 arily will be found arranged paralled 

 the one to the other without rami- 

 fications, are of varying lengths, but 

 of more or less stumpy appearance. 



Staining reaction — The power of 

 resistance to acids disappears 

 almost completely after 2 days 

 growth in culture. 



Biology : cultural characters — Growth 

 is rapid at 37° C, and fairly so at 

 ordinary room temperature. 



Bouillon — Fonnation of a thick 

 veil of granular nature and pale 

 rose tint which creeps up the walls 

 of the tube. A deposit falls to the 

 bottom of the liquid. 



Gelatine — Granular growth of 

 pale rose colour. No liquefaction. 



Agar stab — Surface growth of 

 pale rose colour. 



Glycerine - agar. — Stroke cul- 

 tures ; granular colonies of a dull 

 yellowish-rose colour. 



Potato — Cultures of a pale rose 

 colour ; dry and granular. 



Milk — A surface veil of a pale 

 rose tint. No coagulation. 



Pathogenic properties — Inocu- 

 lated into guinea-pigs the organism 

 gives rise to general congestion, 

 and the formation of local abscesses 

 from which small bacilli resistant 

 to acid can be isolated without 

 difficulty. A tube of glycerine- 

 agar inoculated on the surface 

 from the lesions, presents at the 

 end of 8 days an abundant, 

 wrinkled, dry, and colourless 

 growth of the organism. 



BACILLUS OAUCASIUM (Kern), 



(_Dispora caucasia.') 



Source and habitat — The Kephyr 

 organism. 



Morphology — Rods ; 5-6 /x long, i m 

 broad. Often connected in chains, 

 with gelatinous membrane. 



Staining reaction — Ordinary stains. 



Motility — Slightly motile. 



Spore formation — Bacilli often possess 

 small clear spaces which are 

 probably not spores. 



Biology: cultural characters {includ- 

 ing biochemical features) — Growth 

 at 22 is feeble, 37° C. more favour- 

 able, grows well if milk - sugar 

 added. 



Bouillon — Grows well in milk- 

 sugar bouillon. 



Gelatine plates and tubes — Fresh 

 cultures do not grow well on 

 gelatine ; old cultures do. 



Agar plates and tubes — Whitish- 

 grey colonies on milk-agar. Den- 

 tate margins. 

 Milk — Is not coagulated, little 



