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most watery leaves, suffer most. Atmospheric conditions have great influ- 

 ence, and on them depends the more dehcate, or coarser development of the 

 leaves and .especially of their cuticule. The year 1905 furnished the best 

 proof in New York State. Its warm, misty, spring weather left the foliage 

 very tender. Many apple growers declared that there was greater injury in 

 that year than benefit from spraying with Bordeaux mixture. Hedrick 

 cites examples in which spraying was unusually injurious when the following 

 weather continued moist, while 8 days later after dry weather had set in the 

 s])raying did not have any bad effects. 



Fis-. 170. Young- apples with one-sided malformation, after spraying- with Bordeaux 

 mixture. (Aftei' Mediick.) 



^ J 



FiPT. 171. Cross-section through the bark of a IJaldwin apple injured by spraying? 

 with Bordeaux mixture. (After Hedrick.) 



Wc have borrowed from the above mentioned author some illustrations 

 of fruit and leaves which have been injured by spraying. The injury at 

 first appears on the fruit in the form of small brown specks which spread to 

 extensive rust markings (Fig. 169). If these injuries to the upper surface 

 occur during the period of swelling, the growth of the fruit may liecome 

 irregular (Fig. 170), or gapping cracks may be produced in young apples. 

 Fruit thus injured becomes mealy and easily decays. 



Microscopic investigation of the brown spots shows that the cuticle 

 covering with its wax coating is destroyed (Fig. 171). The walls of the 

 adjacent epidermal cells and the exposed flesh become greatly thickened and 



