378 



BACTERIAL DISEASES OF PLANTS 



states that stocks of Kieffer and Winter Nelis on the Pacific 

 Coast are quite resistant, the blight on sensitive varieties often 

 stopping at the point of union when these stocks have been used. 

 Out of season the only means of obtaining material suitable 

 for inoculation is by the use of a forcing house, by use of young 



FIG. 292. Surface and buried colonies of Bacillus amylovorus from agar 

 poured plates, (a) The buried colonies have vague, fuzzy margins. X 7. Age, 

 4 days. Plated from an apple, in 1905. It was with descendants of this isolation 

 that Dr. Rudolph Aderhold, of Berlin, obtained his infections. From the unlike 

 appearance of the buried and surface colonies he thought at first, so he told me, 

 that I had sent him a contaminated culture, (b) Plated from an apple limb in 

 1915. Buried colonies not fuzzy but also infectious (see Figs. 281, 296). 



seedlings, or on cut shoots by the simple means described under 

 Type, which, however, sometimes fails. 



As material for inoculation, streaks on agar or potato may be 

 used, or bouillon or potato-broth cultures. 



