﻿Halsted : Exposure and fungous Diseases 025 



bacteria. The warmth of the sunny side may have been sufficient 

 to make the difference observed. 



All the circumstances may have combined to bring about the 

 results that were so strikingly evident. The bending of the plants 

 and the swinging of the foliage to the eastward, the inclining of 

 the pods and the exposing of the upper surface, that would natur- 

 ally receive the drips from the diseased leaves, the autumn sun 

 during the afternoon, either adding the required warmth for the 

 germs or partially scalding the side most exposed and thus render 

 the tissues more susceptible to attack are all still open questions. 



One cannot but wonder what the result might have been had 

 the plants been pressed back into place after the storm or a portion 

 of the plot been shaded or even if the rows had run east and west 

 instead of north and south. 



If spores pass through the air, as is the common belief, there is 

 nothing particularly obscure in the observations in the asparagus 

 field, and the hollyhock rust upon the upper side of the petiole is 

 only an instance of the drips from an infested leaf naturally reach- 

 ing the nearest side, while the bacteriosis of the bean deals with 

 the unequal conditions for growth upon different sides of the bean 

 pod due to more favorable ones obtaining upon the one than the 

 other. Doubtless many other instances like the ones cited may 

 be found when one is upon the watch for them. 



Rutgers College. 



