THE FUNGI WHICFI CAUSE PLANT DISEASE 



45 



strict!}' intercellular. Wound inoculations in muskmelon generally 

 gave complete decay in from three to seven days. Similar inocula- 

 tion of citron and cucumbers resulted in decay, though inoculation 

 into squash did not. No decay of musk- 

 melon followed applications of the bacteria 

 to unbroken surfaces. 



B. mycoides Flugge. (Group number 

 -22.1 8-.) 



Rods thick, 0.95 x 1.6-2.4 n, usually in 

 long threads, sporiferous. Spores elliptical, 

 1.3-1.48 X 0.7-0.9 mm. Gelatine colonies 

 white with mycelium-like outgrowths; gela- 

 tine liquefied. Pelhcle formed in broth. 

 Gram positive. 



Tliis common soil organism has been held 

 responsible for a disease of beets. 'i*^ 



B. nicotianEe Uyeda is ascribed as the 

 cause of a tobacco wilt in Japan "'■ ^^^ which 

 closely resembles that caused by B. sola- 

 nacearum in America. 



The bacillus is 1-1.2 x 0.5-0.7 m with 

 rounded ends, actively motile by peritri- 

 chiate flagella. Spores are produced. A 

 complete physiological studj^ is to be found 

 in the articles above cited. 



Bacillus oleae (Arc.) Trev. (Group num- 

 ber -22.333-0—.) C. 0. Smith describes 

 the organism as a motile rod with rounded 

 ends, 1.5-2.5 x 0.5-0.6 /jl. On agar slant 

 growth thin, gray-white, spreading; colonies 

 circular, whitish. On gelatine no liquefac- 

 tion. Milk not coagulated. Distribution of 

 flagella not stated. 



In oleander tubercles on leaves and twigs, 

 and in olive tubercles C. O. Smith "^ found 

 bacteria which he regards as this species. Upon puncture inocu- 

 lation in both olive and oleander, tubercles were produced. Con- 

 trols were not diseased. The organism was reisolated from the 



Fig. 30.— Cultures of B. 

 nielonia on silicate jelly 

 slants, 12 davs' growth, 

 (30° C.) After Gid- 

 dings. 



