THE FUNGI WHICH CAUSE PLANT DISEASE 39 



This he demonstrated b}^ culture and cross inoculation in fruits to 

 be identical with the pear blight organism, though inoculations in 

 plum twigs did not give disease, presumably due to the high re- 

 sistance of this plant. Similarly Paddock has shown this organism 

 to attack the apricot.'"' Detmers has reported what she regarded 

 as this bhght caused by this Bacillus on blackberries." 



Other hosts are hawthorn, shad bush, mountain ash. 



By inoculations with pure cultures of the apple body-blight 

 bacteria, blight upon twigs and blossoms was produced by Whetzel 

 in 1906,'- thus proving the identity of these two forms of disease, 

 an identity asserted first by Burrill.'*' 



Fig. 25. — B. aroidese. After Townsend. 



B. apii (Brizi.) Mig.'^ is reported as the cause of a celery rot, 

 which is possibly identical with a bacterial rot reported earlier 

 by Halsted-'^ 



B. araliavorous Uyeda, described on Ginseng in Korea is per- 

 haps also the cause of soft rot of Ginseng in America.'^ The 

 organism was isolated and studied by Uyeda who made inocula- 

 tions. 



Pseudomonas araliae and Bacillus koraiensis were also com- 

 monly present in the Oriental disease.'' 



B. aroideae Town. (Group Number 221.2223022.) '3 



This organism was described in 1904 as the cause of soft rot of 

 calla '^ corms and leaves. The bacteria were present in almost 

 pure culture in affected tissue and by puncture inoculation in pure 

 culture produced the tjrpical disease in a few days. 



Townsend regarded the organism as distinct from B. carotov- 

 orus, B. oleraceae, B. hyacinthi septicus and Pseudomonas de- 



