480 MICRO-OKGANISMS IN WATER 



'WHITE BACILLUS' (Maschek) 



LIQUEFIES GELATINE 



Authority. — Maschek, Die Bakterien der Nutz- und Trinkwdsser, Adametz, 

 Vienna, 1888. 



"Where Found.— In water. 



Microscopic Appearance.— Short bacillus with rounded ends. 



Cultures. — 



Gelatine Plates. — Circular colonies with a white centre. Under a low 

 power they look bright yellow. The gelatine is liquefied in three days. 



Gelatine Tubes. — Forms a funnel-shaped depression aheady after two 

 days, and at the end of four days the whole of the gelatine is liquid. 



Agar-agar, — Grows rapidly, without any characteristic appearance. 



Potatoes. — Produces a white expansion, which later (four weeks) becomes 

 brown in colour. 



BACILLUS CEASSUS AEOMATICUS 



LIQUEFIES GELATINE 



Authority.—Tataroil, Die Dorpater Wasserhacterien, Dorpat, 1891. 



Where Found. — In well-w^ter in Dorpat. 



Microscopic Appearance. — Fat double bacillus having a distinct compres- 

 sion, 3*5 to 5-0 /i long and 1*5 pL wide, with rounded ends. The poles stain more 

 strongly than the centre. Produces also variously bent, and also long threads. 

 Gives rise to round spores on agar-agar cultures. 



Cultures.— 



Gelatine Plates.— Forms cup-shaped liquefying colonies in the centre, 

 at the bottom of which is seen a small white pellicle, somewhat resembling a 

 rosette in appearance, surrounded by a greyish round circle with radial streaks. 

 With a low power the depth colonies are yellow brown discs, with fine granular 

 contents; the periphery is broken up into large rounded lappets, resembling the 

 petals of a flower. The surface colonies are yellow brown in the centre, and 

 are filled with granular contents ; the edge is paler in colour, and is not at first 

 easily distinguished from the adjacent gelatine; but later the periphery exhibits 

 short and fine hairy extensions. 



Gelatine Tubes. — Produces a circular white expansion, greyish in colour 

 towards the edge, which has a radially streaked appearance. The liquefaction 

 proceeds rapidly in a funnel-shaped depression, and a white pellicle forms on 

 the surface which later on sinks to the bottom. A dirty white deposit is 

 produced, and a fresh pellicle is formed on the surface. 



Agar-agar and Glycerine-agab. — Forms a white shining slimy and thin 

 expansion, and a white deposit. 



Blood Serum. — Produces a narrow milk-like streak, at the bottom of which 

 drops collect, which gradually sink down into the condensed water at the 

 bottom of the tube ; but they remain isolated, and do not combine either with 

 the water or each other. 



Broth. — Benders it turbid, with a dirty white deposit. 



Potatoes. — A light brown smooth and shining growth soon covers the 

 whole surface. 



HemarkSa — The above name is given to this organism on account of the fatness 

 of the bacilli and the fruit-like odour given off by the gelatine-plate cultures. 



