446 MICRO-OKGANISMS IN WATEH 



YELLOW BACILLUS' (Lustig) 



I LIQUEFIES GELATINE | 



Auth-Ority. — Lustig, Dkignostik der Bakterien des ^Vassers, 1893, p. 78. 



Where Found. — Frequently found in the Cagliari water supply. 



Microscopic Appearance.— Short, thin bacillus with rounded ends, occur- 

 ring usually in long, bent or spiral-shaped threads, consisting sometimes of 

 100 individual bacilli. It is not motile. 



Cultures. — 



Gelatine Plates. — After three days small grey dots appear, which under a 

 low power are seen to be round, oval, or irregular in shape, golden yellow in 

 colour, and with an irregular serrated edge. From the periphery delicate ex- 

 tensions stretch into the surrounding gelatine. The surface colonies are similar 

 in appearance. Later on the gelatine in the immediate vicinity becomes liquid, 

 and at the end of ten days the colony is seen to rest in a hollow, having lost 

 its shape, but still of a golden yellow colour. 



GijLATiNE Tubes. — Grows slowly, forming at the end of tAvo days a small 

 slimy drop resembling chloride of gold in colour. In the depth a yellow 

 thread-like growth appears, from which fine, short, lateral extensions penetrate 

 the gelatine. About the fourth day a small funnel-shaped depression is visible, 

 at the bottom of which lies a slimy, golden yellow drop ; later on the sides of 

 the funnel also become coated with yellow slime. The liquefaction proceeds 

 slowly. 



Agak-agar. — Grows more rapidly than on gelatine, and produces a straw- 

 yellow expansion. 



Potatoes. —Forms a very restricted growth, coffee-yellow in colour. 



Remarks. — It will only grow between 15° and 22° C. 



BACILLUS FLAVOCOEIACEUS 



Authority. — Adametz and Wichmann,Die Bakterien der Nutz- tend Trink- 

 wdsser, Vienna, 1888. 



Where Found. — In water. 



Microscopic Appearance. — Very small bacillus growing together in zoogloea. 

 It is not motile. No spore formation observed. 



Cultures. — 



Gelatine Plates. — Forms circular sulphur-yellow colonies. Under a low 

 power the centre appears yellowish brown, surrounded by a clear yellow zone. 

 The young circular as well as the older irregularly shaped colonies are coarsely 

 granular in appearance. No liquefaction takes place. 



Gelatine Tubes. — Slight granulated clouded growth on the surface and in 

 the depth. 



Remarks. — Its growth on other culture media is not recorded. 



