148 MANUAL OF TREE DISEASES 



the American chestnut may yield a resistant variety which 

 can be grown with relative immunity to this disease. The 

 advertisements of resistant chestnuts at this time, however, 

 are misleading, since none has been developed. 



References 



Anderson, P. J., and Rankin, W. H. Endothia canker of chestnut. 

 CorneU Univ. Agr. Exp. Sta. Bui. 347: 531-618, pis. 36-40, 

 flgs. 77-101. 1914. 



Anderson, P. J., and Babcoek, D. C. Field studies on the dissemination 

 and growth of the chestnut tree blight fungus. Pennsylvania 

 Chestnut Tree Blight Com. Bui. 3 : 1-32. 1913. 



Clinton, G. P. Chestnut bark disease. Connecticut Agr. Exp. 

 Sta. Rept. 36 : 359-453, pis. 21-28. 1913. 



Giddings, N. J. The chestnut bark dise^,se. West Virginia Agr. 

 Exp. Sta. Bui. 137 : 209-226, figs. 1-12. 1912. 



Heald, P. D. The symptoms of chestnut tree blight and a brief de- 

 scription of the blight fungus. Pennsylvania Chestnut Tree 

 Blight Com. Bui. 5 : 1-15, pis. 1-16. 1913. 



Metcalf, H., and Collins, J. F. The control of the chestnut bark dis- 

 ease. U. S. Dept. Agr. Farmers' Bui. 467 : 1-24, figs. 1-4. 1911. 



Rankin, W. H., Field studies on the Endothia canker of chestnut in 

 New York State. Phytopath 4 : 233-260, pi. 11, figs. 1-2. 1914. 



Anonymous. Treatment of ornamental chestnut trees affected with 

 the blight disease. Pennsylvania Chestnut Tree Blight Com. Bui. 

 2 : 1-7. 1912. 



Strumella Canker 



Caused by Strumella coryneoidea Sacc. and Winter 



This canker occurs on chestnut but is more destructive on 

 various species of oak. On chestnut the sunken cankers are 

 distinguishable from the Endothia canker or blight, but in 

 general the tree is very similarly affected. The first signs of 

 the developing canker on smooth-barked trees appear as yellow- 

 ish or brownish slightly raised areas around a branch stub. 

 Many black nodules an eighth of an inch in diameter are 

 formed on the surface of the affected bark. When the bark 

 is peeled from the cankers, sheets of pure white or only 



