BY R. GREIG SMITH. 4:55 



production of gas in ordinary nutrient gelatine marks it as being 

 new. Its closest ally appears to be Bad. sinuosum. 



Bacterium minutum, n.sp. 



Shape, etc. — A small cocco-bacterium measuring - 4 -.d-b-Q-l /u. 

 It is actively motile and is not stained by Gram's method. No 

 spores were observed. It grows well at 37°. 



Agar plate. — A translucent white, amoeboid colony quickly 

 grows over the surface. The amoeboid processes are narrow and 

 radiate from a central point. The structure is homogeneous and 

 the margin smooth. 



Agar stroke. — A white, moist glistening, raised growth becomes 

 amoeboid at the base. It may produce gas bubbles in the 

 medium. 



Gelatine plate. — -The colonies are white and of the B. coli type. 

 When magnified the deep colonies are irregular or rounded and 

 either dark brown or opaque. The surface colonies are trans- 

 parent yellowish, grained or contoured, and with an erose, rounded 

 margin. 



Gelatine stab. — The stab becomes filiform and there is formed 

 a flat, irregularly spreading nail-head. The surface growth 

 becomes glistening, slightly depressed and contoured. Some 

 specimens produce gas bubbles in the medium. 



Glucose-gelatine. — There is a considerable development of gas, 



Bouillon. — The medium becomes turbid and there is formed a 

 filamentous precipitate but no film. There is no indol produced. 



Nitrate-bouillon. — Nitrate is strongly reduced to nitrite. 



Milk. — The medium is not coagulated in the cold. The reac- 

 tion is acid and coagulation occui'S on warming. 



Potato. — There is formed an irregular, canary-coloured growth, 

 sharply raised from the medium, which becomes dark and bluish 

 in colour. 



The organism was frequently found in the water. It has its 

 allies in the B. coli and suipestifer groups. The potato growth is 

 characteristic. 



