260 BACTERIOLOGY 



consequently been already described in the chapter on 

 the 'Bacteriological Analysis of Air.' It is usually found in 

 longish chains upon the surface of fermenting urine (see 

 fig. 34, p. 107). 



Lundstroem found that two kinds of staphylococcus are 

 also endowed with this property, viz. the Staphylococcus 

 ureae candidus and the Staphylococcus ureae liquefaciens. The 

 former develops shining white deposits upon the gelatine 

 without liquefying it, the latter liquefies it. 



Miquel encountered amongst the water bacteria 

 numerous varieties possessing the same power. They are 

 for the most part bacilli, only a few being micrococci ; 

 amongst the latter are found three which liquefy gelatine. 

 According to Leube, a variety of sarcina is also to be included 

 with these micro-organisms. 



The Micrococcus ureae liquefaciens described by the last- 

 named observer forms small chains and liquefies gelatine 

 slowly. 



Leube isolated a Bacillus ureae from ammoniacal urine, 

 consisting of short stout rods, the growth of which does not 

 liquefy gelatine. The colonies on the gelatine plate are at 

 first very transparent ; their coalescence gives the gela- 

 tine on that spot the appearance of a slab of ground glass. 

 The margins are indented in consequence of irregularity of 

 growth. In thrust-cultures also grey processes appear, ex- 

 tending out from the needle-track, and these grow at room 

 temperature. 



Of other micro-organisms which decompose urea the 

 TIrobacillus Freudenreichii and the Urobacillus Maddoxii 

 should also be mentioned. The former grows best on gela- 

 tine at 20 C., forming a milk-white coating on the surface, 

 while deeper a cavity, filled with a turbid stringy fluid 

 develops. Liquefaction of the gelatine progresses slowly, 

 and the liquefied region gradually clears, a white slimy 



