FIRE-BLIGHT OF APPLE, PEAR, ETC. I CAUSE 



373 



shoots will soon begin to show the blight. To keep the cut sur- 

 face from drying out, the jar of water should be covered with a 

 tall bell jar; it should also be protected from direct sunshine. 

 The shoots should be of sensitive varieties, e.g., Clapp's Favorite 

 or Flemish Beauty, and the organism must be virulent. 



The following unsupported or wholly erroneous statements 

 respecting the pear blight organism have gained more or less 



FIG. 288. Section from a disintegrating pear fruit (like Fig. 284), showing 

 Bacillus amylovorus between and in the cells. Photomicrograph by the writer. 

 X 1000. 



currency, viz., that it is a Micrococcus, that it is non-flagellate 

 (the flagella are hard to stain), that it is a rapid destroyer of 

 starch, that it produces gas and more specifically carbon dioxide 

 or hydrogen, that it produces butyric acid, that it will not grow 

 on agar, that it does not liquefy gelatin, that it is yellowish, 

 that it is red or reddish, that it cannot be found swarming 

 in the leaves, that it causes a disease of peach trees and of Lom- 

 bardy poplar trees, that it commonly passes the winter in dead 

 limbs or in the earth, that it cannot be cross-inoculated from 

 apple to pear and quince or vice versa, that it never enters the 



