GENUS BACILLUS 349 



whitish gray; colonies sink on liquefaction of medium; lique- 

 faction progresses quite rapidly and a thick whitish scum is 

 formed. 



Potato. On potato a very vigorous grayish mealy or more 

 membranous growth extends over the surface. % 



Bouillon. A thin membranous pellicle forms on the 

 surface. In some cultures the liquid becomes cloudy and in 

 others it remains clear beneath the membrane. 



Milk. Milk becomes thickened, peptonized and slightly 

 alkaline. 



Life conditions and properties. It grows best at room 

 temperature. It does not produce indol. A soluble toxin is 

 not known. 



Pathogenesis. It is not considered a disease producing 

 organism. Charrin and de Nittis x cultivated it on blood 

 media and passed it through animals until it acquired some 

 virulence. Silberschmidt 2 and others have reported cases of 

 its being pathogenic. In the earlier work, reference is made 

 to the possibility of B. subtilis being a prototype of Bact. an- 

 thracis and some workers thought they had changed B. subtilis 

 into virulent anthrax bacteria. Such results have not been 

 recorded within recent years. 



BACILLUS PRODIGIOSUS (EHRENBERG) FLUGGE. 



Synonyms. Mon'as prodigiosa Ehrenberg 1 ; Bacterium 

 prodigiosum Schroter 2 ; Micrococcus prodigiosus Cohn. 3 



Place in nature. This is a non-pathogenic microorgan- 

 ism. It is of interest in this connection simply because it may 

 occur as a contamination and it is also interesting in the study 

 of certain properties of bacteria, especially pigment produc- 



1 Charrin and de Nittis. Compt. rendu. de la Soc. de 'Biologic, 

 Vol. XLIX (1897) p. 711. 



-Silberschmidt. Ann. de 1'Inst. Pasteur, Vol. XVII (1903) p. 268. 



1 Ehrenberg. Verhandl. der Berliner Akademie, 1839. Cited by 

 Migula. 



-Schroter. Cohn's Beitrage zur Biologie, 1872. 



'' Cohn. Untersuchungen iiber Bakterien, I, 1872. 



