A DIFFERENCE IN THE iMETABOLISM OF THE SEXES 37
Observations of above 4000 cases show that among horses the more the parent animals differ in color the more the female foals outnumber the male. Similarly, in-and-in bred cattle give an excessively large number of bull calves. Liaisons produce an abnormally large proportion of females, 1 incestuous unions, of males. 2 Among the Jews, who frequently marry cousins, the per cent, of male births is very high.
According to Mr. Jacobs' comprehensive manuscript collection of Jewish statistics .... the average proportion of male and female Jewish births registered in various countries is 1 14.5 males to 100 females, whilst the aver- age proportion among the non-Jewish population of the corresponding coun- tries is 105.25 males to 100 females His collection includes details of
118 mixed marriages; of these 28 are sterile, and in the remainder there are 145 female children and 122 male that is, 118.82 females to 100 males. 3
The testimony is also tolerably full that among metis and among exogamous peoples the female birth rate is often excess- ively high. 4
Viewed with reference to activity the animal is an advance on the plant, from which it departs by morphological and physio- logical variations suited to a more energized form of life ; and the female may be regarded as the animal norm from which the male departs by further morphological and physiological varia- tions. It is now well known that variations are more frequent and marked in males than in females. Among the lower forms, in which activity is more directly determined mechanically by the stimuli of heat, light, and chemical attraction, and where in general the food and light are evenly distributed through the medium in which life exists, and where the limits of variation are consequently small, the constitutional nutritive tendency of the female manifests itself in size. Among many cephalopoda and cirripedia, and among certain of the articufata the female is larger than the male. Female spiders, bees, wasps, hornets, and but- terflies are larger than the males, and the difference is noticeable
1 A. VON OETI 1. Aufl., p. 56.
' DOSING, Die Rtgulirung det Geschltchtsvcrhdltnisses, p. 237.
RMARCK, /of. /., pp. 479 and 481 n. 4 (/. \YKSTERMARCK, ibid. % pp. 476-83.
