Murphy — On the Cause of Rolling in Potato Foliage. 183 



It was proved that capsid bugs {Calocoris bipunctatus) and jassids 

 {Typhlocyba Ulmi) act as carriers of leaf-roll in the field. 



Aphides {Myzm Fersicae), when they occur on the sprouts of unplanted 

 tubers, were also shown to be carriers of leaf -roll, and to be capable of giving rise 

 to the earliest infestation of the foliage with these insects. 



The vapour of tetraehlorethane was found a safe and efficient medium for 

 ridding sprouted tubers of aphides. 



LITERATURE CITED. 



1. Atanasoff, D. — A Study into the Literature on Stipple-Streak and related 



Diseases of the Potato. Med. v. d. Ijandbouwhoogeschool, Wageningen, 

 Deel 26, 1922. 



2. DoBY, G. (and J. Bodnar, in part). — Biochemische Untersuchungen iiber die 



BlattroUkrankheit der Kartoft'el. Zeitschr. f. Plianzenkrank., 21 Bd., 

 pp. 10-17 and 321-36; 22 Bd., pp. 204-11 and 401-3; 25 Bd., pp. 4-16; 

 1911-15. 



3. EsMARCH, F. — Zur Kenntnis des Stoffwechsels in blattrollkranken Kartoffeln. 



Zeitschr. f. Pflanzenkrank., 29 Bd., pp. 1-20, 1919. 



4. HiLTNER, L. (and G. Gentner, in part). — I'eber den Zusammenhang der 



BlattroUkrankheit der Kartoft'el mit der Starkeanhaufung in ihren 

 Blattern, etc. Prakt. Bliit. f. Plianzenbau, 16 Jahrg., pp. 138-41; 17 

 Jahrg., pp. 15-19; 1918-1919. 



5. jMurphy, p. a. — Investigation of Potato Diseases. Dominion of Canada 



Dept. of Agric, Bull. 44 (Second Series), 1921. 



6. Neger, F. W.— Die Blattrolll5;rankheit der Kartofl'el. Ein Beitrag zur 



Aetiologie der Krankheit. Deut. landw. Presse, 45 Jahrg., pp. 469-70, 

 1918. 



7. Neger, F. W.— (Same general title.) Zeitschr. f. Pflanzenkrank., 29 Bd., 



pp. 27-48, 1919. 



8. OoRTWiJN IBoTjES, J. C. — Die BlattroUkrankheit der Kartoft'elpflanze. 



Inaug. Dissert. Landw. Hochschule, Wageningen, 1920. 



9. QuANJER, H. M. — Sur la fonction du tissu cribble. Med. v. d. Landbouw- 



. hoogeschool, Wageningen, Deel 16, pp. 95-104, 1919. 



10. QuANJER, H. M., H. A. A. van der TjKk, and J. Oortwijn Botjes. — Nature, 



■ mode of dissemination, and control of phloem necrosis (leaf-roll) and 

 related diseases, i. a. Sereh. Med. v. d. Rijks Hoogere Land — . . . 

 Bouwschool, Wageningen, Deel 10, 1916. 



11. QuANjER, H. M., J. C. DoRST, M. D. Dijt, and A. W. v. d. Haak.— De 



iMozaiekziekte van de Solanaceeen hare Verwantsehap met de Phlocem- 

 necrose en hare Beteekeiiis voor de Aardappelcultuur. Med. v. d. Land- 

 bouwhoogeschool, Wageningen, Deel 17, 1919. Summary with addi- 

 tional matter in Phytopath., vol. 10, pp. 35-47, 1920. 



12. ScHANDER, R., and M. v. Tiesenhausicn. — Kann man die Phloemnekrose als 



Ursache oder Symptom der BlattroUkrankheit der Kartoft'el ansehen? 

 Abstract in Zeitschr. f. Pflanzenkrank., 25 Bd., pp. 16-18, 1915. 



13. ScHULTz, E. S., and D. Polsom. — Leaf Roll, Net-Necrosis, and Spindling- 



Sprout of the Irish Potato. Jour. Agr. Res., vol. 21, pp. 47-80, 1921. 



14. Spieckermann, A. — Beitriige zur Kenntnis der Bakterienring- und Blatt- 



rollkrankheiten der Kartoffelpflanze. Jahresber. d. Ver. f. angew. 

 Botanik, 8 Jahrg., pp. 1-19 and 173-7, 1911. 



15. VocHTiNG, H. — Ueber die Bildung der Knollen. Bibliotheca botanica, 



Heft. 4, pp. 4 et seq., Cassel, 1887. 



SOIliNT. PKOC. R.D.S., VOL. XVII, NO. 20. 2k 



