DESCRIPTION OF SPECIES 



417 



BACILLUS PLUORESCBNS 



SCHUYLKILLIBNSIS 



(Wright). 



Source and habitat — Milk. 

 Morphology — 2 i* long, -8 ix broad ; 



sometimes occurs in chains. 

 Staining reaction — Ordinary aniline 



stains. 

 Biology : cultural characters {includ- 

 ing biochemical features). 



Gelatine plates and tubes — Large 

 liquefying colonies. Green and 

 granular. Later becoming sur- 

 rounded by a clear space. In 

 tubes slow growth. At first a 

 shallow pit and later a horizontal 

 liquid layer with a scum and a 

 precipitate. 



Agar tubes — A thin white moist 

 growth. The agar becomes green. 

 Potato — Thin moist brown 

 spreading growth. 



Milk — Curdles in 3 days at 20° C. 

 Sometimes fails to curdle. Makes 

 the milk alkaline. 

 Aerobic. 



BACILLUS, No. 41 (Conn). 



Source and habitat — Milk from 

 Uruguay. 



Morphology — A bacillus ; i-i /t by 6 ^ 

 (longer on potato than agar). Some- 

 times in twos or in chains. 



Staining reaction -Ordinary aniline 

 stains. 



Spore formation — None. 



Biology : cultural charcKters {includ- 

 ing biochemical features) — Grows 

 best at 20" to 23° C. ; only slightly at 

 35° ; killed at 60° C. in 10 minutes. 

 Bouillon — 



Gelatine plates and tubes — A 

 smooth, round colony under sur- 

 face ; grey bead-like colony on 

 surface ; non-liquefying ; non- 

 chromogenic. In stab-culture a 

 slight " needle growth " ; spreads 



over surface as a moist, white, thick 

 mound or nail growth. 



Agar plates and tubes — An 

 abundant white, smooth, glistening 

 growth. 



Potato — Raised thick white layer. 

 If ver}' moist, whiter ; if dr}', 

 yellower. Grows profusely. A 

 pleasant aromatic odour produced. 



Milk — Does not curdle at 20° or 

 35° C. ; becomes translucent and 

 brownish in 2 to 3 weeks. Reaction 

 slightly acid. Produces a pleasant 

 aroma. Much used for cream 

 ripening and butter making. 



Aerobic. 



Non-pathogenic. 



BACILLUS PRIBURGBNSIS, No. 1 

 (Korn). 



Source and habitat — Butter of Friburg. 



Morphology J form, dimensions, and 

 manner of grouping — In prepara- 

 tions made from the organs of an 

 inoculated animal, the bacilli very 

 much resemble in shape and size 

 the B. tuberculosis of Koch. In 

 bouillon, the shape ver>' much 

 resembles the B. coli. It is, how- 

 ever, a little longer and slightly 

 curved. On agar the bacilli are 

 slightly thinner. In old cultures 

 upon agar and serum, they assume 

 the aspect of " Coccothrix." Uj)on 

 potato they appear under form of 

 cocci, diplococci, and specially of 

 short, stout bacilli slightly curved. 

 Upon cooked beetroot at the end 

 of 3 or 4 days the organisms 

 resemble staphylococci. They are 

 shorter when grown at ordinary 

 temperature than when grown at 

 37° C. 



Staining — Stains well by the method 

 of Ziehl-Neelsen, but is a little less 

 resistant to acids than the bacillus 

 tuberculosis. It does not stain 

 well with ordinary aniline stains. 



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