222 FARMYARD MANURE 



for growth is about 32 C. It will not grow on ordinary media, 

 but thrives when provided with urea and ammonium carbonate. 

 It is commonly present in manured soils, and is one of the most 

 energetic of all uro-bacteria, being able to ferment large amounts 

 of urea in a short time. 



Urea Gelatine (p. 224). The surface colonies are round, 

 moist, greyish-white, slow in growth, often not more than 3 mm. 

 in diameter after a week. The centre after a time becomes 

 somewhat concave and the medium partially liquefied. Deep 

 colonies are at first small, yellowish or brownish in colour : 

 they may come to the surface and grow out into a thin trans- 

 parent film i ///or more across. 



Urea bouillon (p. 223). The liquid ' becomes slightly turbid 

 and develops an odour of ammonia. No growth occurs on 

 ordinary gelatine, potato or agar media, or in bouillon or milk. 



Urobacillus Schutzenbergii, I., Miquel. A motile, short, 

 rod-shaped organism, without spores, i (^ long, .3 to .5 /a, thick, 

 generally occurring in pairs. 



Gelatine. The surface colonies are round, semi-transparent, 

 milky, 'and cup-shaped. The gelatine is liquefied. 



Urea-gelatine, (p. 224). On 2 per cent, urea-gelatine the 

 colonies are i to 2 mm. in diameter, and surrounded by a halo 

 of crystals ; no liquefaction occurs. 



Agar. On agar the colonies are greenish white. 



Urobacillus Schutzenbergii, II., Cambier, is a motile aerobic 

 organism, 3 to 5 & long, .6 ^ thick, without spores. 



Gelatine. The colonies are white, and produce rapid liquefac- 

 tion of the medium. 



Agar. The surface colonies are white, small, with a slightly 

 pearly lustre. 



Bouillon is rendered turbid, and remains so for some time, 

 with little precipitate. 



Urobacillus Duclauxii, Miquel. A common uro-bacillus in 

 river and canal water, and a facultative anaerobe. The cells are 

 2 to 10 ^ long, .6 to .8 ^ thick, and motile in alkaline media, 



