DISEASES OF ROSES 101 



6. Wolf, F. A. The perfect stage of the rose Actinonema. 



Science N. S. 35: 152. 1912. 



7. Salmon, E. S. Sphgerotheca pannosa (Wallr.) Lev. In A 



Monograph of the Erysiphacese. Mem. Torr. Bot. 

 Club 9: 65-70. 1900. 



8. Stewart, F. C. Powdery mildew. In Notes on New York 



Plant Diseases, I. New York (Geneva) Agr. Exp. Sta. 

 Bui. 328: 390-391. 1910. 



9. Woronichin, N. N. Bui. Trimest. Soc. France 30:391-401. 



1914. 



10. Norton, J. B. S., and White, T. H. Rose mildew. Maryland 



Agr. Exp. Station. Bui. 156: 73-80. 1911. 



11. Stewart, V. B. Experiment for the control of rose mildew. 



In Dusting nursery stock for the control of leaf diseases. 

 New York (Cornell) Agr. Exp. Sta. Circ. 32: 9. 1916. 



12. Maynard, S. T. Treatment of mildews upon plants under 



glass. Jour. Mycol. 6: 16-17. 1891. 



13. Massey, L. M. The crown-canker disease of rose. Phyto- 



path. 7:408^17. 1917. 



14. Smith, E. F., Brown, N. A., and Townsend, C. O. Crown- 



gall of plants: its cause and remedy. U. S. Dept. Agr., 

 Bur. Plant Indus. Bui. 213: 1-200. 1911. 



15. Smith, E. F., and I'ownsend, C. 0. A plant tumor of bacte- 



rial origin. Science, N. S. 25:671-673. 1907. 



16. Townsend, C. O. A bacterial gall of the daisy and its rela- 



tion to gall formations on other plants. Science N. S. 

 29:273. 1909. 



Explanation of Plates. 



Plate 1. Rose plants affected with crown-canker. Fig. 1. Stem of an 

 Ophelia plant artificially inoculated with myceUum of fungus. Fig. 2. 

 Hoosier Beauty plant showing cracking at crown. Fig. 3. American 

 Beauty plant showing black water-soaked area at crown. Figs. 1 and 2, 

 natiu-al size; Fig. 3, three-fourths natural size. 



Plate 2. Fig. 1. Plant affected with crown-gall. Note the large gall 

 formed at the crown of the plant. Fig. 2. Black-spot lesions on rose leaf. 

 Natural size. 



