490 MIORO-OIIGANISMS IN WATER 



COCCUS B. (I'ouiin) 



Authority. — Foutin/Bakteriologische Untersuchimgen von Hagel,' Centrai- 

 blattf. Bakteriologie, vol. vii., 1890, p. 372. 



Where Found.— In hail. 



Microscopic Appearance — Large round coccus (about 1 /x), occurs generally 

 in twos, threes, or short chains. Is easily coloured by Gram's method, as well 

 as by the ordinary stains. 



Cultures.— 



Gelatine Plates. — The colonies on the sixth day are circular, about 1 mm. 

 in size, white and slightly raised. Under a low power they are seen to be grey, 

 yellowish green discs, which are slightly granular towards the periphery ; some- 

 times the latter is smooth, and sometimes lobular. No liquefaction takes place, 



Gelatine Tubes. — Forms a flat-headed, nail-like growth on the surface, 

 -whilst later on lateral branchings extend from the needle's path in the depth, 

 resembling the growth of the B. murisepticus (see p. 428). 



Agah-agab. — Produces a smooth-rimmed, shining, white expansion. 



Potatoes. — Grows slowly, producing a thin, almost transparent, whitish 

 expansion. 



Remarks. — It is pathogenic to white rats when injected into the abdominal cavity, 

 the cocci being found in the blood, liver, and spleen, and the animal dying in from 

 five to six hours. 



COCCUS A. (Foutin) 



I LIQUEFIES GELATINE | 



Authority. — Poutin, ' Bakteriologische Untersuchungen von Hagel,' Central- 

 blattf. Bakteriologie, vol. vii., 1890, p. 372. 



Where Found.— In hail. 



Microscopic Appearance. — Kound cocci, which are easily stained, and also 

 by Gram's method. 



Cultures. — 



Gelatine Plates.— On the fourth day slightly prominent and white discs 

 are visible. Under a low power they are seen to be dark in the centre, the 

 periphery being lighter and slightly granular. 



Gelatine Tubes. — Forms a yellowish nail-head growth on the surface, but 

 very little is visible in the depth. Liquefaction begins on the fifth to sixth day, 

 and proceeds very slowly, whilst a deposit collects at the bottom. 



Agar-agar.— Produces a shining, smooth, pale, rose-coloured expansion, 

 with a sharply-defined periphery. 



Potatoes.— Resembles the growth of the typhoid bacillus (see p. 410). 



Remarks. — It is not pathogenic to mice and guinea-pigs. 



