RESULTS OF CASTRATION IN DUCKS. 53 



the anthers. The female reproductive organs, forming the "ears," 

 arise from axils of the leaves about midway of the stalk. In 

 some varieties secondary stalks called suckers may arise near 

 the base of the plant. They are usually devoid of ears, but 

 almost always produce a tassel. 



Sometimes, however, kernels of corn develop on the tassels. 

 These appear to be always associated with a smut fungus. These 

 kernels were often very numerous on the tassels of suckers, oc- 

 casionally a fair resemblance to an ear being formed. 



Stamens are less easily found on the ear but they may occur 

 at its apex. This may mean that the germ cells, which normally 

 would produce ova, develop into male cells, but since the ear is 

 morphologically the equivalent of a branch it may mean only 

 an abortive attempt at the development of the branch. Since 

 these observations were made, Professor Morgan has kindly 

 called my attention to the splendid work of Bleringhem on maize. 

 My results as far as they go entirely confirm Bleringhem, though 

 the alteration in sex patency appears to be brought about by 

 a different cause. 



The case of Lychnis dioica, studied by Giard, is interesting. 

 'The young is hermaphrodite, but in certain individuals the 

 ovaries abort, in others the stamens remain rudimentary." 1 Other 

 instances in plants are cited by Bleringhem. 



These instances are sufficient to show that what seems to be 

 only one sex may really be both sexes with one of them suppressed. 

 Compare also Smith's studies on Inachus. 



At the present time, the evidence available in regard to the 

 nature of sex and its determination is very contradictory. The 

 observations of Smith on parasitic castration in Crustacea, the 

 experiments of Morgan with Drosophila, and the studies of Wilson 

 and others indicate that the female is pure for femaleness, but 

 that the male is a sex hybrid of maleness (dominant) and female- 

 ness. Diametrically opposite evidence is afforded by the experi- 

 ments of Doncaster on Abraxis, followed by experiments on other 

 forms by several other investigators, which favor Bateson's the- 

 ory of a sex heterozygous female (femaleness dominant) and a sex 

 homozygous male. There are still other experiments which favor 

 neither view. 



J The quotation is taken from Wheeler's paper. 



