Page:Popular Science Monthly Volume 80.djvu/495

Rh For criminality, Goring's results will strike many as surprisingly low. They are:

An interesting point of an entirely different nature has been raised by Heron who in a study of the distribution of sex in human families finds, "that in the free mating of man, families with a preponderance of female or male elements are not drawn upon equally with families in which the sexes are more equally balanced."

From the notion that in marriage "opposite poles attract" the step to the conclusion that dissimilar are more fertile than similar unions is so easy that it has sometimes been taken, though without any valid evidence in justification.

Fay considers that marriages of the deaf are possibly slightly less fertile than those of hearing persons. When both partners are deaf the percentage of sterile marriages seems higher and the mean number of children in fertile mariagesmarriages [sic]lower than in unions in which one member of the pair is a hearing person.

Homogamy for stature and for eye color Pearson (Phil. Trans. Roy. Soc., A, Vol. 195, pp. 148-150, 1900; Proc. Roy. Soc. Lond., Vol. 66, p. 323, footnote) has considered Galton 's data without arriving at final conclusions. De Candolle (fide Westermarck, "History of Human Marriage," p. 335) states that the number of children is considerably smaller when the parents have the same color of eye than when they were contrasted. Wittrock (Ymer, Vol. 5, pp. vii-ix, 1885) was unable, on Swedish materials, to detect any difference in fertility between the two classes of marriages. have been considered in relation to fertility.

But as yet the data are far too meager for such complex problems. The whole problem of the relationship between homogamy and fertility is open to investigation.

The statistical facts reviewed in this essay make it highly probable that a great variety of physical and mental characters influence human