262 MANUAL OF BACTERIOLOGY. 



monia. It has been known to produce general septicemia* 

 It is pathogenic for guinea-pigs and rabbits, in whom it may 

 produce septicemia. In animals it may lead only to local 

 suppuration, from which they may recover, being made im- 

 mune from subsequent infection with this organism. It ap- 

 pears that an antagonism exists between the products of the 

 Bacillus pyocyaneus and the anthrax baciUus. Rabbits which 

 have been inoculated with cultures of the anthrax bacillus 

 may recover if they are injected shortly after with a culture of 

 the Bacillus pyocyaneus. 



There appears to be a whole group of fluorescent organisms 

 of sHghtly different characters which closely resemble, one 

 another, all classed as pyocyaneus. 



Bacillus proteus. — ^A bacillus with rounded ends, vary- 

 ing much in length, breadth 0.4 to 0.6 n; frequently appearing 

 as short ovals like micrococci; sometimes growing out into 

 long filaments, so that it is said to be pleomorphic. Rounded 

 involution forms occur. It is not stained by Gram's method. 

 It is motile. Spore formation has not been observed. It is 

 aerobic and facultatively anaerobic. It grows rapidly at or- 

 dinary temperatures. This organism was originally described 

 by Hauser as three different species — Proteus vulgaris, which 

 was said to Hquefy gelatin rapidly, Proteus mirdbilis, which 

 liquefied gelatin slowly, and Proteus Zenkeri, which did not 

 liquefy gelatin. It seems probable that these organisms were, 

 in fact, varieties of the same species, now called BaciUus proteus. 

 Upon gelatin-plates the colonies present a characteristic phe- 

 nomenon, when seen under the low power, in the projection 

 of processes which subsequently change their form and position, 

 and which may become entirely detached from the original 



* Lartigau. Philadelphia Medical Journal. September 17, 1898. Journal 

 Experimental Medicine. Vol. III. 1898. Perkins. Journal Medical Re- 

 search. Vol. VI. 1901. 



