1 68 Journal of Agricultural Research voi. iv. no. 2 



(38) Rolfs, F. M. 



1902. Potato failures. A preliminary report. Colo. Agr. Exp. Sta. Bui. 70, 

 20 p., 12 pi. 



(39) 



1904. Potato failures. A second report. Colo. Agr. Exp. Sta. Bui. 91, t,^ p., 



5Pl- 



(40) RosTRUP, Emil. 



1889. Oversigt over de i 1888 indl0bene Foresp0rgsler angaaende Sygdomme 

 hos Kulturplanter. Voredrag i det Kgl. Landhusholdningsselskab 20. 

 Marts 1889. In Tidsskr. Landokonom., Raekke 5, Bd. 8, p. 744-751. 

 Reprint, Kjpbenhavn, 1890. Original not seen. 



(41) 



1894. Phoma-AngriffbeiWurzelgevvachsen. InZtschr. Pfianzenkrank., Bd. 4, 



P- 322-323- 



(42) Shaw, F. J. F. 



1912. The morphology and parasitism of Rhizoctonia. In Mem. Dept. Agr. 



India, Bot. Ser., v. 4, no. 6, p. 115-153, 11 pi. 



(43) TuLASNE, L. R., and Tulasne, Charles. 



1851. Fungi Hypogaei ... 222 p., 21 pi. (partly col.) Parisiis. 



(44) WOLLENWEBER, H. W. 



1913. Pilzparasitare Welkekrankheiten der Kulturpfianze. In Ber. Deut. Bot. 



Gesell., Bd. 31, Heft i, p. 30. 



PLATE XVI 

 Isolation cultures from sugar-beet seedlings. 



Fig. I. — Rhizoctonia sp. 



Fig. 2. — Pythium debaryanum. 



