BACTERIA IN RELATION TO PLANT DISEASES. 



promptly and very well on cooked potato where it is viscid after some days. We have 

 tried to grow it with negative or unsatisfactory results on standard +15 beef peptone agar, 



Fig. 7l4.f 



Fig - 710 '* r- 7t + 



Fig. 7U.J 



corn meal agar, potato agar, banana agar, carrot agar, Loeffler's malt extract agar, and 

 standard beef peptone agar with oxalic acid (prepared for fungi). Neither have we been 



*FlG. 710. Stems of Dactylis glomerata from Denmark, showing dwarfing and distortion due to Rathay's disease. 



fFlG. 716. Stem of Dactylis glomerata from Austria, photographed in 1913 from alcoholic material collected by 

 Rathay. Leaves stuck together above and culm below pushing side-wise out of the sheath. Original in Museum of 

 Lehr Anstalt at Klosterneuberg. 



JFlG. -jic. A. Cross-section of stem of Dactylis glomerata, showing bacterial layer (white mass) entirely sur- 

 rounding the culm, and separating it from the enveloping leaf-sheath. B. Cross-section from another plant, showing 

 partial separation of an inner and outer leaf-sheath by the bacteria (white line at the top). Both were cut and photo- 

 graphed in Washington from Rathay's material. 



