SUMMER NUMBER 5 
- duced winged forms of the rose aphid Nectarophora rosae. As 
shown above this was not true in the case of another species of 
rose aphid. No winged forms were produced even when the sec- 
ond and third generations were raised on cuttings in salt solu- 
tions by transferring the aphids from one cutting to another as 
often as they showed signs of wilting. In the same way three 
generations of Myzus persicae were raised on orange cuttings 
with no noticeable effect as compared with the checks on grow- 
ing trees. Two generations of Lachnus pini, and one of Aphis 
gossypui were also raised on cuttings in solutions of magnesium, 
of sodium, and of citrus acid, and in all cases without results to 
substantiate Clarke’s statement. 
Morgan (24) in discussing Balbiani’s work of raising sexual 
and parthenogenetic forms of aphids says that a female pro- 
ducing parthenogenetic young continued to produce them when 
placed on a dying stem. He concludes that food does not effect 
the mode of reproduction unless the organism is “predisposed to 
submit to its influence.” In another paper Morgan (25) gives 
the results of several attempts to produce sexual aphids, and 
_ finally concludes that sexual forms are not due to external con- 
ditions, however important these factors may be in cyclical 
changes in sex production. We can also say the same regarding 
wing formation in aphids. 
External conditions must require more than one generation 
to produce their effects, and when once effected the condition 
of that individual cannot be altered. Even in the second and third 
generations no positive results of their influence on wing forma- 
tion were obtained. 
REFERENCES CITED 
1. Ashmead, Wm. H.—Insect Notes from General Bulletin. Bulletin No. 
2. Fla. Agr. Expt. Sta. 
2. Berger, E. W.—19th Annual Report of Entomologist. Fla. Agr. Expt. 
Sta. 
3. Buckton—Monograph of British Aphids. 
4. Chittenden, F. H.—Some Insects Injprious to Cabbages, Cucumbers 
and Related Crops. Va. Truck Expt. Sta. Bul. No. 2. 
5. Chittenden, F. H.—The Melon Aphis. Bureau of Entomology. Circular 
80. U.S. D. A. 
6. Clarke, Warren T.—A List of California Aphididae. Canadian Ento- 
mologist. Vol. XXXV., p. 247 (19038). 
Comstock, J. H.—Insect Life. 
Comstock, J. H—Manual for the Study of Insects. 
Davis, J. J—A List of the Aphididae of Illinois, with Notes on Some 
of the Species. Journal of Economic Entomology. Vol. III, No. 6 
(1910). 
OES! 
