172 



ESSENTIALS OF BACTERIOLOGY 



Properties. Very motile; liquefy gelatin rapidly; a pecu- 

 liar sweetish odor and a blue pigment are produced in the 

 cultures. 



Growth. Develops readily at ordinary temperature, grow- 

 ing quickly and mostly on the surface; it is aerobic. Agar 

 plate: In two or three days a greenish iridescence appears 

 over the whole plate. 



A bright green at first, causing fluorescence; then later a 

 blue pigment in deeper portion. 



* '' % ' 



Fig. 83. Bacillus pyocyaneus, from an agar-agar culture (X 1000) 

 (Itzerott and Niemann). 



Gelatin Stab-cultures. Mainly in upper strata, the lique- 

 faction funnel shaped, the growth gradually settling at the 

 bottom, a rich green shimmer forming on the surface, and the 

 gelatin having a deep fluorescence. 



Potato. The potato is soaked with the pigment, a deep 

 fold of green occurring on the surface. 



Indol is produced. 



In ear abscesses pure cultures have been found. 



Bacillus fluorescens, found in water, is considered identical 



