372 



Bulletin 164 



upper surface of the leaf may be gradually arched from base to 

 tip. When the leaf is full grown, the diseased areas may be red- 

 dish green ; but usually the green color is largely lost and a pale 

 discoloration characterizes diseased parts. The frontispiece and 



64. — A terminal shoot with both leaves and tiuig affected by the leaf-curl 



fu7igus. 



figure 64 show the appearance of the disease on a cluster 

 of leaves terminating a shoot. Figure 64 also shows another 

 point to be observed. Not only are leaf and leaf-stalk affected, 

 but the terminal part of the shoot becomes much enlarged, and 

 also pale in color. The fungus is then thoroughly established in 



