NON-PATHOGENIC BACTERIA 103 



days on gelatin very minute points, which in ten days have the 

 size of a cent. The colonies grow in concentric layers. 



Micrococcus Ureae (Pasteur and Van Tiegham) .Origin. 

 Decomposed urine and in the air. 



Form. Cocci, diplococci, and streptococci. 



Properties. Decomposes urea into ammonium carbonate; 

 does not liquefy gelatin. 



Growth. Grows rapidly, needing oxygen; can remain sta- 

 tionary below o C., growing again when a higher temperature 

 is reached. 



Colonies on Plate. On the surface like a drop of wax. 



Stab-cultures. Looks like a very delicate thread along the 

 needle-thrust. 



Other bacteria are found in urine in various pathologic proc- 

 esses, such as tubercle bacilli, typhoid bacilli, gonococci, and 

 other pyogenic organisms. 



The Urobacillus liquefaciens, found by Schnitzler and 

 Krogius in cystitis, is supposed to stand in close relationship to 

 this disease. 



Spirilla. A number of non-pathogenic spirilla have been 

 described. 



Spirillum Rubrum (Esmarch) . Origin. Body of a mouse 

 dead with septicemia. 



Form. Spirals of variable length, long joints, flagella on each 

 end; no spores. 



Properties. Does not liquefy gelatin; very motile; pro- 

 duces a wine-red pigment, which develops only in absence of 

 oxygen. 



Growth. Can grow with oxygen, but is then colorless; grows 

 very slowly; ten to twelve days before any sign; grows best at 

 37 C. 



Gelatin Roll-cultures. Small, round; first gray, then wine- 

 red colonies. 



Stab-cultures. A red-colored growth along the whole line; it 

 is deepest below, getting paler as it approaches the surface. 



Spirillum Concentricum (Kitasato) . Origin. Decom- 

 posed blood. 



