386 



Diseases of Economic Plants 



CHESTNUT 



Bark-disease ^^^- *^- ^^^ {Endothia parasitica (Miirrill) A. & 

 A.).-— First noted in 1904 by Merkel in New York, this 



disease has spread 

 with a rapidity and 

 destructiveness with- 

 out parallel in plant 

 pathology. Its dis- 

 tribution in 1918 is 

 indicated in Fig. 205. 

 The disease extended 

 by natural agencies 



Fig. 203 



■ Chestnut-bark 

 Beattie. 



Fig. 204. — Chestnut- 

 bark disease, show- 

 ing the sporiferous 

 pustules. After U. 

 S. Bur. PI. Ind. 



through the native chestnut forests from Maine to Vir- 

 ginia, but shipments of nursery stock have been responsi- 



