52 THE FUNGI WHICH CAUSE PLANT DISEASE 



cited as the cause of a bacterial corn disease but the evidence of 

 causal relation as well as the identity of the germ are not clear. 



B. zinzgiberi Uyeda causes a disease of Zinzibar,^"* B. sac- 

 chari and B. glangse are on sugar cane as the possible cause of 

 sereh. , 



An organism called Clostridium persicae-tuberculosis by 

 Cavara ^^* is mentioned as cause of knot on peach trees. 



Less known bacterial plant diseases. The literature abounds 

 in references to what are regarded as cases of plant bacteriose, 

 cases which as yet rest upon very incomplete evidence. In many 

 of these bacteria are found in abundance in the diseased tissue 

 but pathogenicity has not been proved by inoculation nor pure 

 cultures made. Among such incompletely studied diseases may 

 be mentioned those of geranium; i^'i''* celery,^** onion,"' ^^'' ^*** 

 cucumber,^*^ orchard grass,*®'' lettuce,**' ^°' (one lettuce disease 

 is due to a motile rod-shaped organism cultured and inoculated 

 but not named, **^) strawberries,**^*^ mulberry,**' hemp,*'" calceo- 

 laria.*'* 



There are also several obscure bacterial beet diseases; another 

 cabbage rot due to Pseudomonas; "^ a decay of apples said by 

 Prillieux to be due to a Bacillus; *'' the blossom-end-rot of tomatoes 

 which is perhaps bacterial; *'* a cyclamen leaf spot; *'* a juniper dis- 

 ease; *™ a pine gall; *" an ash bark disease; *'* and an ash canker; *'* 

 an ivy canker; **" a grape disease;" a salsify rot; *** a carnation 

 spot; **^ and a banana disease; *^' a gummosis of tobacco; **'' a 

 disease of tobacco seedlings; *^^ also perhaps the serious widespread 

 mosaic disease of tobacco and an orchid gunmiosis.*'* 



