BACILLI 43' 



BACILLUS HYALINUS 



| LIQUEFIES GELATINEJ 



Authority. Jordan, A Ecport on certain Species of Bacteria observed in 

 Sewage, State Board of Health, Massachusetts, 1890, 'Purification of Water 

 and Sewage,' p. 835. 



Where Found. Isolated from the sand of a tank used for filtering sewage 

 at Lawrence. 



Microscopic Appearance. Large, long, stout bacilli, with rounded ends. 

 Usually occurring in short strings. No spore formation observed. About 3'6 

 to 4 p long and 1-5 p broad. Very motile. 



Cultures. 



GELATINE PLATES. Grows rapidly and is visible in twenty-four hours. The 

 centre is dark, surrounded by a broad, translucent zone, whieh gives a hazy 

 appearance to the colonies. Under a low power the contents are coarsely 

 fibrillar, with short fibrils radiating from the edge. The colonies in two days 

 are about 1 and l.y c.c. in diameter, the contour is evenly round, the interior 

 slightly translucent ; the rim is distinct, opaque, yellowish, whilst towards the 

 edge the radiating fibrils are still visible. 



GELATINE TUBES. Forms in two days a long, narrow, funnel-shaped growth. 

 The gelatine, which is rapidly liquefied, is at first cloudy, and a precipitate 

 forms at the bottom of the funnel. In about eight days a lustrous, tenacious, 

 white scum forms on the surface ; the gelatine, which is completely fluid, is 

 perfectly transparent, and at the bottom of tbe tube there rests a slight floccu- 

 lent deposit. 



AGAR-AGAR. Forms rapidly a spreading, dry, dull greyish growth. It is 

 tough and rather thin. After about four or five days small warty projections 

 appear. It grows well in the depth. 



POTATOES. Forms a spreading, dry, whitish grey growth, but less rapidly 

 than on agar. Later small protuberances appear on the surface. 



BROTH. Benders it turbid, with a thick pellicle and a stringy precipitate. 



MILK. In seven days strongly coagulated. Acid reaction. 



Remarks. It grows better at 37 than at 21 or 23 C. Eecluces nitrates vigor- 

 ously and rapidly. (See tinder B. cloacae, p. 433.) 



