[13.]

Guyer, M.F. Being Well-Born. Indianapolis, 1916, p. 51.

[14.]

Tower, W.L. (et al.). Heredity and Eugenics. Chicago, 1912, pp. 164, 254-5.

[15.]

Conklin, E.G. Share of Egg and Sperm in Heredity. Proc. Nat. Acad. of Sc., Feb., 1917.