284 BACTERIAL DISEASES OF PLANTS 



On the fruit, the fleshy portion of the pericarp is the chief 

 seat of the disease (Figs. 225and226), but the bacteria also burrow 

 inward and often infect the interior of the pod and the surface 

 of the ripening seeds. The seed itself may also be attacked. 



When the infections are through stomata, the first signs 

 of the disease on the pods are minute, green spots, each surround- 

 ing a stoma. Although very small in this stage (I have often 

 seen them on my sprayed plants when they were less than one- 

 fourth millimeter in diameter), their color difference makes them 

 conspicuous. Do not confuse with stigmonose. 



Fig. 217. — Distortion of bean leaves due to Bacterium phaseoli. From the 

 same series of plants as Fig. 216, but the leaves were very stnall when sprayed 

 and most of the stomata were not open. Infection confined principally to the 

 veins. 



In seasons of exceptional dewfall or rain the entire crop either 

 of bush beans or of lima beans may be destroyed, especially in 

 case of susceptible varieties. 



The geographical distribution of this disease is unknown. 

 It occurs in many parts of the United States, probably in every 

 state in the Union, but little is known concerning its occurrence 

 in other parts of the world. Delacroix once reported it from 

 France, but subsequently decided that his disease was different. 

 I am inclined to think, since seeing his dried material and making 

 sections of it (cultures failed), that his first conclusion is the cor- 

 rect one, and that it does occur in France. I looked for it in 



