82 ESSENTIALS OF BACTERIOLOGY. 



Stab Cultures. A cup-shaped liquefaction along the needle 

 thrust, with a sparse growth, the liquefied portion appearing 

 blue. 



Fluorescent Bacteria. Several kinds present in water. 



Bacillus Erythrosporus. (Eidam.) 



Origin. Drinking water and putrefying albuminous solutions. 



Form. Slender rods often in short threads, with spores of 

 oval shape, and appearing as if stained with fuchsin. 



Properties. Motile ; does not dissolve gelatine ; produces a 

 greenish-fluorescent pigment which appears yellow in reflected 

 light, but green on transmitted light. 



Growth. SQmewhat quickly ; facultative anaerobic ; growth 

 only at ordinary temperatures. 



Plates. White colonies, with greenish-yellow fluorescence 

 around each colony. Under microscope the periphery appears 

 radiated. 



Stab Cultures. Good growth along the needle thrust ; the 

 whole gelatine gives out the fluorescence. 



Bacillus Fluorescens Liquefaciens. 



Origin. Water, and from conjunctival sac. 



Form. Very fine little rods ; no spores. 



Properties. Motile ; forms a greenish-yellow fluorescent pig- 

 ment ; liquefies gelatine. 



Growth. Rapid only at ordinary temperatures, and strongly 

 aerobic. 



Plates. Round colonies, cup-shaped depressions, the solid 

 gelatine that remains becoming colored with greenish-yellow 

 fluorescence. 



Stab Culture. On the surface, air-bubble depressions ; the 

 white colonies in the bottom of these depressions, and the solid 

 gelatine around the inoculation shining with the fluorescence. 



Phosphorescent Bacteria. Six varieties of phosphorescent 

 bacteria have been described ; they are found usually in sea- 

 water, or upon objects living in the sea. 



Bacillus Phosphorescens Indicus. (Fischer.) 



Origin. Tropical waters. 



Ibrm. Thick rods, with rounded ends, sometimes forming 

 long threads. 



