(141) 
Pemberton, C. E. and Willard, H. F. Fruit-Fly Parasitism in Hawaii during 1916. 
(Journ. Agric. Research Washington XII [1918], p. 103—108.) 
— Interrelations of Fruit-Fly Parasitesin Hawaii. (Ibidem p. 285—295, Pl. <—XIIL) 
— — Work and Parasitism of the Mediterranean Fruit Fly in Hawai during 1917. 
(Ibidem XIV [1918], p. 605—610.) = 
— — Contribution to the Biology of Fruit-Fly Parasites in Hawaii. (Journ. Agric. 
Research Washington XV [1918], p. 419—465, Pl. XXXII, 41 Textfigs.) 
Petherbridge, F. R. Potato spraying trials.. (Journ. Bd. Agric. Great Britain XXV 
[1919], p. 1166—1172.) 
Petri, L. Über die Ursachen der Erscheinung bleifarbiger oder silberweißer Blätter 
an den Bäumen. (Ann. R. Istit. super. Forest. naz. II[1917], 11 pp. 1 Taf. 2 Abb.) 
Pierce, W. Dwight. Weevils which Affect Irich Potato, Sweet Potato, and Yam. 
(Journ. Agric. ResearchWashington XI1[1918], p.601—611,PI.XXVIII—-XXXIV.) 
Pollock, J. B. The longevity in the soil of the Sclerotinia causing brown rot of stone 
fruits. (Rept. Michigan Acad. Sci. XX [1918], p. 279—280.) 
Pratt, 0. A. Soil Fungi in Relation to Diseases of the Irish Potato in Southern Idaho. 
° (Journ. Agric. Research Washington XIII [1918], p. 73—99, Pl. A—B, 4 Textfigs.) 
Raeder, H. Schwarze Johannisbeeren als Raupenvertreiber. (Prakt. Ratgeber i. Obst- 
u. Gartenbau XXXV [1920], p. 187.) 
Ravenna, C. Sulla adesivitä degli anticrittogamici a base di rame contro la perono- 
spora della vite. (La Rivista ser. 5. XXI [Conegliano 1915], p- 210—214.) 
Reckendorfer, F. Der Rotbrenner. (Allgem. Weinzeitg. XXXVI [1919], Nr. 36.) 
Regan, W.S. Progress ofexperimentsfor destroying Ribeswithchemicals. (Rept.White 
r Pine Blister Rust Control, Amer. Plant Pest Committee Bull. II [1919], p. 15—16.) 
Regnier, R. Sur le chancre bacterien du peuplier. (Micrococeus Populi). (Compt. 
Rend. Acad. Sci. Paris CLXIX [1919], p. 85—88.) 
Reijne, A. Eenige opmerkingen over .de bestryding van insecten, schadelijk voor 
Liberiakoffie. (Departement van den Landbouw in Suriname, Bulletin Nr. 37." 
'[Oetober 1919], 18pp. 8°.) i 
Reinking, Otto A. Host Index of Diseases of Economic Plants in the Piälpiäek 
(The Philippine Agriculturist VIII [1919], p- 38—54.) 
— Philippine economio-plant diseases. (Philipp. Journ. Sci. XIII Be. Sect. 
p: 165—216; 217—274. Pl. I-XXLU, Fig. 1-43.) 
Reynolds, E. S. Two tomato diseases. (Phytopathology VII [1918], p. 535—542, 
Fig. 1—2.) 
Rhoads, A. S., Hedgeock, G. G., Bethel, E. and Hartley, C. Host relationships of the 
North American rusts, other than Gymnosporangiums, which attack conifers. 
.(Phytopathology VIII [1918], p. 309—352.) _ 
Richter, W. A. Die Kalkschwefelbrühe, verbunden mit Nikotin-Sulfat, eine neue 
Spritz-Zusammenstellung amerikanischer Obstzüchter. (Prakt. Ratgeb. i. Obst- 
u. Gartenb. XXXV [1920], p. 213.) : ; ; 
Ritzema, Bos. J. Ziekten bij Kool I.. Knolvoet. (Tijdschr. Plantenziekten XXIV 
- [1918], Bijblad p. 26—35, 3 Fig.) > ; 
Rivera, V. Ricerche sperimentali sulle cause predisponenti il fr to alla „nebbia“ 
Erysiphe graminis DC. (Men. Staz. Patolog. veget. Roma [1915], 42 pp. Fisg.) 
Roepke, W. Over de bloemknopwants van de Thee. (Mededeel. Proststation voor 
 Thee Nr. LXVII [1919], p- 1—6, Fig. 1-5.) 
‚Rosenbaum, J. and Ramsey, G. B. Influence of Temperature and Precipitation on 
„the Blackleg of Potato. (Journ. Agric. Research Washington XIII [1918], 
p- 507—513, 1 Fig.) 
