Studies on Marriage in Toshima Island of Izu, Tokyo.

Part V. On the Consanguineous Marriage in Toshima Island

Abstract

5. Consanguineous marriage; The frequency of consanguineous marriage was 11.9 per cent, among which the marriage between consins were the most. The 1.62 per cent of the whole population were psychotic. This percentage is rather high comparing with other island of Izu. It was also noticed that there would be some consanguineous relations among these psychotics.
Using Prof. Koike's classification, it was recognized that finger-prints were frequent in the type S and in the type OW in hand.