468 MICROORGANISMS IN WATER 



BACILLUS GASOFOEMANS ( ' Gasbildender Bacillus ' ) 



LIQUEFIES GELATINE 



Authority. Eisenberg, Bakteriologische Diagnostik, 1891, p. 107. 



Where Found. In water. Found also by Tils (Zeitsclirift filr Hygiene, 

 vol. ix. p. 315) in Freiburg water. 



Microscopic Appearance. Small, very motile bacilli. No spore formation 

 observed. 



Cultures. 



GELATINE PLATES. Forms rapidly cup-shaped, liquefying depressions.. 

 Under a low power the contents are seen to be greyish, and bubbles of gas are 

 often visible. 



GELATINE TUBES. Kapidly liquefies the gelatine, producing along the 

 needle's puncture a stocking -like depression, whilst in the still solid gelatine 

 bubbles of gas appear the whole length of the needle's path. It will not grow 

 at higher temperatures. 



POTATOES. Grpws rapidly, producing a dark yellow, later reddish brown,, 

 slimy expansion (Tils, loc. cit.}. 



BACILLUS THALASSOPHILUS 



| LIQUEFIES GELATINE 



Authority. Russell, ' Untersuchungen iiber im Golf von Neapel lebende 

 Bacterien,' Zeitschrift filr Hygiene, vol. ix., 1891, p. 190. 



Where Found. Obtained frequently in anaerobic cultures of sea-mud. 



Microscopic Appearance. A slender bacillus of variable length, having a 

 tendency to form filaments. It is capable of slow movements. Forms spores 

 at the end of the rod. Will not stain with Loeffler's solution or fuchsin, but 

 young cultures stain well with Ziehl's solution ; old cultures, however, take up 

 but little even of this stain. 



Cultures. 



SEA-WATER GELATINE TUBES. In from two to three days colonies in the 

 shape of small clouded bubbles appear at the bottom of the needle's path in 

 the depth ; above these other colonies make their appearance, until finally a 

 long, grey, semi-transparent, liquid, sack-shaped mass is formed, in the upper 

 portions of which gas collects. The gelatine is rapidly liquefied, although much 

 more slowly towards the surface. This liquefaction is produced by a pepton- 

 ising ferment elaborated by the bacillus, but extending beyond the limits of its 

 growth. The turbid fluid becomes subsequently clear. 



GELATINE PLATES. When an ordinary gelatine plate is covered by another 

 glass plate the colonies appear in from two to three days. Under a low power 

 they exhibit a very thin network composed of filaments, which penetrate the 

 gelatine, but do not give rise to any definite shape. A great deal of gas forms 

 in the colonies, and on raising the superficial plate an intense smell of skatol 

 is given off. The isolated colonies soon coalesce, and the whole of the gelatine 

 becomes fluid. 



AGAR-AGAR. Grows very slowly in the depth at a distance of 2 cm. from the- 

 surface. 



