136 BACTERIOLOGY 



colour is also developed along the whole length of the thrust- 

 canal in the gelatine. 



Bacillus aquatilis, which was described by P. Frankland, 

 exhibits short, feebly motile rods. On gelatine plates 

 the colonies develop in the deeper parts, and spread thence 

 to the surface, liquefying the gelatine. From the surface 

 bundles of filaments extend to the periphery. In thrust- 

 cultures a weak yellowish coloration first shows on the 

 surface, and liquefaction takes place comparatively late. 

 The growth on agar is restricted to the line of inoculation, 

 and on potato the colonies show a similarly meagre de- 

 velopment. The bacillus was found in the water of deep 

 wells sunk in a chalky soil. 



Bacillus aquatilis sulcatus. — -Weichselbaum found four 

 micro-organisms in the water of the high-level water-works 

 of Vienna at a time when water from the Schwarza was 

 laid on,' and these he designates as Bacillus aquatilis 

 sulcatus 1-4. The first three forms have motile elements, 

 those of the fourth variety are shorter, and do not move. 

 On the gelatine plates colonies develop which are thicker 

 in the centre than at the periphery, and possess a distinctly 

 coloured border, while on their surface furrows can be seen 

 with a low power crossing one another at the most varying 

 angles, and this network of wrinkles is denser in the centre 

 than at the periphery. The points of distinction of these 

 varieties are limited to variations of temperature and 

 differences of odour, which is like that of whey in the first 

 form, resembles urine in the second, and is exceedingly 

 unpleasant in the third, while the cultures of the fourth 

 variety give off no smell. A superficial growth appears 



' The drinking-water supplied to Vienna is brought from the Schneeberg, 

 a distance of 100 kilometers. In summer, however, sufficient cannot be 

 obtained from this source, so that other water must be laid on in addition, 

 and this is derived from the Schwarza, a little river in the vicinity of the 

 Scemmering. 



