Stewart's disease of maize: transmission 175 



is said upon this subject in ''Bacteria in Relation to Plant 

 Diseases," Vol. Ill, pp. 114-127, and if you can find gardens or 

 fields in which this disease has appeared for the first time, pro- 

 cure seeds of the infected varieties from the same seedsman and 

 of the same origin, and repeat the experiment, trying also (as 

 mentioned under Technic) to find the organism in some of the 



Fig. 118 — Single infected and disorganized bundle of sweet-corn stem much 

 enlarged, showing the bacterial mass of Aplanobacter stewarti dark because it was 

 stained red with carbol fuchsin. 



kernels (the vessels toward the base) by means of stained sec- 

 tions and by the agar-poured-plate method. Tell the seedsman 

 the result. 



The disease occurs in the United States every year in many 

 localities where sweet corns are grown for market and the organ- 

 ism may therefore be supposed to winter over in the soil, but 

 in places where it appears for the first time it may be assumed 



