- 107 - 
(168) MARSH, R. W., and PEARCE, T. J. P.. 
1932. Experiments with combined insecticide-fungicide sprays 
for apples. Progress Rpt. L'ristol [England] Univ. 
Agr. and Reft, Res. Sta. Ann. Rpt. 1932: 63-85. 
(169) KELS.iL, A., SPIT TALL, J. P., GORHAM, R. P., and VLVLKSR, G. P. 
1926. Derris as an insecticide. Ontario Ent. Soc. Ann. Rpt. 
(1925) 56: 24-40 
(170) and STU1TZ, H. T. 
1937, Pyre "thrum and derris dust. Ontario Ent. Sec, Ann. Rpt. 
(1936) 67: 20-30. 
(171) KENTUCKY AGPJCIJLTURAL EXPSRIHEFT STATI02! 
1934. [Rctenone] Ky. Agr. Expt. Sta. ^rra. Rpt.- (1933) 46 
(Part I): 42. 
(172) OOWLTONi G. F. , SMITH, C. F. , and UAFJ'STOH, F. C. ■ 
1938, Pea aphid investigations. Utah Acad', Sci. Arts and 
Letters Proc. 15: 71-60. 
(173) and SORB27SON, C. J. 
1937, The pea aphid. Utah Agr. Expt. Sta. Leaflet 76, 4 pp. 
(174)X0L0NLAAL IUSTITUUT TE AMSTERDAM 
1936. Insecticides of derris type. Chem. and Drug. 125: 
244-245. 
(175) -— — 
1936. Plantenziekten en -Flagon. Inlichtingen en onderzoe- 
kingen van de afdeeling haVidelsmuseum in 19 35. 
Amsterdam Kolon. Inst. Ai'd. Handel snuseum. Keded. 
39 (16): 78-102, illu.s. . 
( See ajlso Amsterdam. Kolonial lnstituut.) 
(176) KOPP, A. 
1924. Les derris insecticides. Hev. de Bot. Appl. et d 'Agr. 
Colon. '3ul. 4 (34): 400-402. 
(177) LAAN, P. A. van der 
1935. Bcrichten van de afdeeling Handel smi'-seum van de kon. 
ver. "Koloniaal lnstituut." No. 96, 15 pp. Over de 
houdbaarheid van de figtigheid van dorri : s'p6eder en 
rotenon. Indischc Mercuur 58 (IS): 257-259. r Also 
in Tijdschr. Plantenziekten. 41 (4): 77-87. 1935.] 
(178) 
1956, Verslag ven do Negen-en-Zestigste "Wintorvorgadering dor 
Kcderlandsche Entomologischo Verecniging, ^jristerdam, 
February 23, 1936. 7ijdsc.hr. v. Ent, 79: 52-58. 
(179) LA DUE, J. P. 
1938. Higher ketones as intermediary solvents for derris 
resinatc used in petroleum spray oil. Jour. Eccn. 
Ent. 31: 319-320. 
