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THE AMERICAN NATURALIST [Vol. LII 



Experiment 294.— This was a repetition of the preced- 

 ing experiment, in part simultaneous with it but of 

 shorter duration. The method of conducting the experi- 

 ment was the same as in the preceding experiment. 

 Table II gives the results. 



TABLE II 



Contrasting Two Belated Lines of Macrosiphum solanifolii, One Beared 



July 7 July 



July 13 

 July 14-July 1 



The conclusion is the same as from Table I. Apterous 

 parents give birth more largely to alate offspring, alate 

 parents more largely to apterous offspring. 



Relation of Winged and Wingless Forms to the Sexes 

 Experiment 303. — Just before the sexual phase of the 

 cycle began a line from winged parents was started from 

 a line being reared from wingless parents. In so far as 

 the two were bred simultaneously their progeny are re- 

 corded in Table III. 



Of the sexual offspring, the wingless parents produced 

 exclusively males, while the wingless parents gave birth 

 to a very large majority of sexual females. It may be 



