FIRE-BLIGHT OF APPLE, PEAR, ETC.: CAUSE 



369 



ing, rather slowly liquefying (gelatin, not Loffler's solidified 

 blood serum), more or less viscid (often quite slimy from 

 pear and apple fruits), butyrous on agar and potato (D. H. 

 Jones) aerobic and lacultative anaerobic (with grape-sugar, 

 fruit-sugar, cane-sugar, or malt-sugar), non-gas-forming, sodium 



Fig. 284. — Green pear fruit (Duchess) rotted by Bacillus amylovorus. Result 

 of a pure-culture inoculation. Ooze of bacteria through stomata can be seen 

 in many places above the central area. Below is a larger amount of bacterial 

 ooze from cracks in the vicinity of the needle-wounds. 



chlorid-tolerant, sunlight-sensitive, dry-air-sensitive, rod-shaped 

 schizomycete, growing on the surface of agar-poured plates in 

 the form of circular, small, entire-margined, more or less 

 opalescent white colonies, and in the depths as smaller, some- 

 times ringed, fringed or hazy-margined colonies (our pathogenic 



