BACILLUS ERYTHROSPORUS. 357 



Bacillus fluorescens putidus. 

 This organism occurs frequently in putrefying 



. , , i stinking 



materials ; it imparts to the latter a greenish hue, and bacillus, 

 produces at the same time a smell resembling that of 

 trimethylamine ; it does not liquefy the gelatine.* The 

 organism presents the form of small, short, very actively 

 moving bacilli, with rounded ends. They form in the 

 deeper parts of the gelatine plates very small dark 

 colonies (under a low power), which grow better at the 

 surface, and then present the appearance of round discs, 

 with sharp wavy outlines ; in the centre the remains of 

 the deep-seated colonies appear as a dark speck ; the 

 surrounding mass is yellow, light grey, and finely 

 granular towards the margin. On the third day the 

 colonies have extended markedly on the surface, they 

 present an irregular outline and have a greenish shimmer, 

 in fact the whole plate has a greenish shimmer ; at the 

 same time there is a strong smell resembling that of 

 herring brine. In puncture cultivations a faint grey or 

 milky muddiness develops along the track of the needle, 

 this muddiness extending much more markedly on the 

 surface ; from the third day onwards there appears a 

 greenish coloration of the gelatine gradually extending 

 from above downwards. On potatoes the organisms 

 grow rapidly in the form of a brownish, or at the surface 

 more greyish, thin layer. 



Bacill us erythrosporus . 



This organism was formerly observed by Eidam, and Fluorescing 

 afterwards by Cohn and Miflet, in meat infusion, in reddish* * 

 putrefying albuminous fluids, &c., and was obtained s P res< 

 from the air.t Since that time it has been often 

 observed in a great variety of putrefying fluids as well 

 as in drinking water. It presents the form of thin 

 mobile bacilli with abruptly rounded ends, often forming 

 short threads. At the ordinary temperature two to eight 



* Gottinger hygienisches Institut. 



f Cohn's Beitrdge zur Biologic der Pflanzen, vol. iii., part 1, p. 128. 



