174 BACTERIOLOGY 



or putrefactive alkaloids possessing toxic qualities. Phospho- 

 rescence and a formation of pigment are very often observed 

 in putrefying substances. 



Bacillus fuscus limbatus. — ^This bacillus was discovered 

 by Scheibenzuber at the author's Institute, in putrid eggs 

 smelling distinctly of sulphuretted hydrogen. It consists 

 of short rods seldom united in threads, which display an 

 active motility and do not liquefy gelatine. Small brownish 

 distinctly rounded clumps are at first found on the gelatine 

 plate, and the bacilli are arranged round these in a trans- 

 parent circle, forming a dlear area like a collar, which is 

 twice or three times as broad as the diameter of the original 

 brownish islet in the centre. In thrust-cultures the growth 

 spreads out over the surface, while along the needle- 

 track there appear prominences like the teeth of a saw, or 

 sometimes bowed outwards. The medium shows a dis- 

 coloration round the puncture in the form of a bag with the 

 convexity, downwards and the constricted opening above. 

 This appearance, which is characteristic, shows it to be an 

 organism which, like Bacillus fluorescens non-liquefacie7iH 

 and Bacillus melochloros, imparts its colouring matter to 

 the nutrient medium. On agar and potato a brown growth 

 appears. It thrives at the temperature of an ordinary room, 

 as well as at that of the incubator. 



Proteus. — The varieties of Proteus described by Hauser 

 belong to the pathogenic micro-organisms living in putrid 

 substances. The kinds distinguished are Proteus vulgaris, 

 Proteus mirabilis, and Proteus Zenkeri, organisms which 

 set up putrid decomposition. If animals are inoculated 

 subcutaneously with small quantities of cultures of Proteus 

 toxic phenomena are evoked, and the animals, whether 

 rabbits or guinea-pigs, die in a comparatively short time 

 with the symptoms of a severe peritonitis or enteritis. 

 The toxic action originates in the decomposition of albu- 



