DESCRIPTION OF SPECIES 



cipitate with alkaline reaction. 

 The clear serum becomes rose-red. 

 Aerobic. 



Non-pathogenic. 



Conn describes a variety in the 

 form of a large coccus. 



BACILLUS MEGATHERIUM 

 (De Bary). 



Source and /^«^/A?/ — Decomposing 

 cabbage leaves (De Bary). 



Morphology-^ bacillus with blunt 

 ends 1-6 to 5 M long, -6 to -8 n 

 broad; De Bary described the 

 bacillus as 3 m thick ; often united 

 m strings. 



Staining rmr//^«— Ordinary stains 

 and by Gram's method. 



Flagella; motility ~ ^\o^s motility- 

 many flagella. ' 



Biology : cultural characters {includ- 

 tng biochemical features). 



Bouillon —Cloudy growth with 

 pelhcle. No indol. Formation of 

 HoS. 



Gelatine plates and tubes- 

 Greyish, opaque colonies resem- 

 hhng B. subtilis. Liquefaction. In 

 stab-cultures tube or sack shaped 

 liquefaction takes place, the liquid 

 IS turbid and flocculi of deposit 

 occur. No pellicle. The colonies 

 on gelatine plate form no twisted 

 bands or curls. 



Agar plates and tubes~Whit& 

 to whitish -grey, elevated, moist 

 colonies, with hairy outgrowths. 



Potato— Thick, yellow-coloured 

 growth. 



Milk -Is alkaline and fully acid 

 becomes coagulated and later 

 dissolved. 



Facultative anaerobe. 

 Non-pathogenic. 



425 



many 



BACILLUS MESENTERICUS 

 FUSCUS (Fliigge). 



Source and habitat— Soil, dust, etc. 

 Morphology—Slender rods with round 



ends ; -8 to 2-4 ^ Jong, .7 to -9 /. 



broad. Sometimes forms chains. 

 Staining reaction — Ordinary stains 



and Gram's method. 



Flagellar motility — Motile ; 

 flagella. 



Spore forfnation—Round spores. 



Biology: cultural characters {includ- 

 ing biochemical features). 



Bouillon — Growth makes 



medium cloudy and produces a 

 pellicle. 



Gelatine plates and tubes— Small 

 round grey-white colonies which 

 soon sink in the liquefied medium. 

 Colonies are like those of B 

 subtilis. In stab-culture colony 

 smks into saucer-like depression 

 within 24 hours, the contents of 

 the funnel of liquefaction are cloudy 

 and a whitish-grey film appears on 

 the surface. 



Agar plates and tubes— Round 

 grey colonies, thin and veil-like. 

 Wavy, moist, shining, yellow-brown 

 growth in streak cultures, conden- 

 sation water cloudy with growth ; 

 a yellow precipitate ; and a pellicle 

 on the surface. Sometimes a dry 

 folded growth. 



Potato— hx first growth is moder- 

 ately elevated, greyish - yellow, 

 shining, shmy ; eventually becomes 

 much wrinkled and elevated. 



Milk-At 20" C. does not curdle 

 milk but digests slowly and be- 

 comes alkaline ; at 26° C. curdles 

 m 6 days and digests. Cream 

 ripened with this organism pro- 

 duces butter with no aroma or 

 flavour. 



^^r<7^'^_Facultative anaerobic. 

 Non-pathogenic. 



