8o REPORTS ON INVESTIGATIONS AND PROJECTS. 



Strains, one-fourth of their children will be nervously undeveloped. The 

 consideration of the pedigrees shows that in the families studied the propor- 

 tion of mental defectives has in each of the last two generations been doubled 

 from what it was in the preceding generation. 



CONSANGUINEOUS MARRIAGE AND ITS EEEECTS. 



During a vacation of ten days the Director visited a series of islands off 

 the coast of Maine for the purpose of making a reconnaissance of a suitable 

 locality for studies upon consanguineous marriage and its effects. Visits to 

 both Hancock and Washington counties showed several places in which such 

 consanguineous marriages are unusually frequent, chiefly on account of the 

 barrier of water, and it is proposed, with the voluntary assistance of the 

 people, to see in how far the results have or have not been deleterious. The 

 study will be made by the Eugenics Record Office. 



HEREDITY OF SEX IN A DICECIOUS HERMAPHRODITE PLANT. 



Now that sex is generally regarded as controlled by a sex-determiner in 

 the nucleus, the absence or presence of which results in one sex or the other, 

 peculiar interest attaches to the behavior of sex-inheritance in a partially 

 hermaphrodite species. Suitable material for this study is afforded by the 

 cockle. Lychnis, and for several years past Dr. ShuU has had about an acre 

 of these plants under cultivation. This year his studies on Lychnis have 

 dealt more particularly with the character of the vestigial organs of the one 

 sex in individuals of the opposite sex, in order to learn to what degree the 

 gap between each sex and the hermaphrodite condition is bridged by varia- 

 tions in the development of such vestiges. Only one individual in an aggre- 

 gate of over 7,500 females and hermaphrodites permitted a doubt whether it 

 should be classified as a female with exceptional development of staminodes 

 or a hermaphrodite with aborted stamens. The gap between males and 

 hermaphrodites is closed by the occurrence of every degree of development 

 of female organs, from a minute bristle which is the usual condition in the 

 male to a fully developed and functional ovary; but the number of these 

 intergrading forms is very small relative to the number of normal males. 

 Some evidence has been secured indicating that the eggs of the hermaphro- 

 dites may carry the hermaphrodite character, though heretofore hermaphro- 

 ditism has seemed to be borne only by the sperms, A special series of crosses 

 has been made to test this matter. 



HEREDITY OE EEOWER COLORS. 



Lychnis. — The study of the inheritance of the color of the flowers of 

 Lychnis has been continued. The search for homozygous or pure-bred 

 purple-flowered strains has been rewarded with success in the blue-flowered 

 series, but not in the red. In the latter, failure has again resulted, because 

 in each of the small number of crosses made for this purpose, one of the 



