BACILLI 459 



BACILLUS EADIATUS AQUATILIS 



| LIQUEFIES^ GELATINE 



Authority. Zimmermann, Die Baktcrien unserer Tnnk- und Nutzwasser, 

 insbesondere des Wassers der Chcmnitzer Wasserleitung, Chemnitz, 1890. 



Where Found. In the Chemnitz water supply. 



Microscopic Appearance. Bacilli varying in length, about 0-65 /j. broad ; 

 the shortest rods are about 1-0 /* and the longest 6'5 /x long. Only the shorter 

 rods exhibit slight motility. 



Cultures. 



GELATINE PLATES. After two days in the depth whitish blue centres are 

 visible with irregular contour, and often having a white spot in the centre. 

 Under a low power numerous root-like ramifications are visible, causing the 

 colony to resemble a mould. In three days the colonies are nearly circular, 

 and under a low. power resemble small woolly balls, out of which threads 

 extend. Finally the gelatine is broken at one point, and one or more small 

 drops of liquid resembling water come to the surface. In four days a liquefied 

 cup-shaped depression appears, in the midst of which a circular mass of bac- 

 terial growth, whitish yellow or cream-coloured, is visible; round this is seen a 

 ring composed of the same material, only usually deeper in colour, and delicate 

 rays pass from it to the edge of the depression. 



GELATINE TUBES. Forms on the surface a circular and thin expansion 

 which often exhibits radial foldings, whilst in the depth a funnel-shaped 

 growth is visible, and on the third day liquefaction commences. A yellowish 

 deposit collects at the bottom, and in the turbid liquid flocculent particles are 

 visible. 



AGAR-AGAR. Grows slowly at first, forming a smooth, shining expansion, 

 brownish yellow in transmitted light, and pale greenish blue in reflected light. 



POTATOES. Forms a yellow ochre, sometimes reddish brown, expansion. 



BACILLUS PLICATUS 



LIQUEFIES GELATINE | 



Authority. Zimmermann, Die Bdkterien unserer Trink- und Nutzwasscr, 

 insbesondere dcs Wassers der Chcmnitzer Wasserleitung, Chemnitz, 1890. 



Where Found. In the Chemnitz water supply. A Bacillus plicahis 

 obtained from air has been previously described by Percy and G. C. Frank- 

 land (' On some new Micro-organisms obtained from Air,' Phil. Trans., vol. 

 clxxviii., 1887, p. 273), but the organism obtained from water does not re- 

 semble it. 



Microscopic Appearance. Small thin bacillus, about 0-45 /i broad and 

 - 48 yu long, with rounded ends. It occurs mostly in pairs, but also in fours, 

 and hanging together in larger numbers. It is not motile. 



Cultures. 



GELATINE PLATES. In the depth the colonies are yellowish white and some- 

 what irregular and elongated in shape. Under a very low power distinct lobu- 

 lations are visible, which increase when the colony reaches the surface, recall- 

 ing a yellowish white mulberry in appearance. They are seen, when rather 

 more magnified, to be greyish yellow, irregular in contour, and covered on the 

 surface with innumerable small protuberances. 



GELATINE TUBES. Forms an irregular yellowish white expansion, which 

 becomes drawn together and wrinkled. After eight to fourteen days it sinks, 

 and the gelatine becomes gradually liquefied. In the depth an abundant 

 growth is visible, consisting of strings of yellow-white granular heaps. 



POTATOES. Forms a thin expansion, which soon becomes dried and assumes 

 a greyish yellow and brittle appearance. 



