[1668] Darwin, ‘Animals and Plants under Domestication,’ vol. ii. pp. 148-160.

[1669] Peschel, loc. cit. p. 9.  Eyre, loc. cit. vol. ii. p. 324. Lumholtz, loc. cit. p. 273.

[1670] Meyer, loc. cit. p. 186.

[1671] Taplin, loc. cit. p. 14.

[1672] Broca, loc. cit. p. 36.

[1673] Peschel, loc. cit. p. 8.

[1674] v. Görtz, ‘Reise um die Welt,’ vol. iii. p. 288.

[1675] Hensen, ‘Die Physiologie der Zeugung,’ in Hermann, ‘Handbuch der Physiologie,’ vol. vi. pt. ii. p. 191.

[1676] Darwin, ‘Animals and Plants under Domestication,’ vol. ii. pp. 182, et seq.

[1677] Jacobs, ‘On the Racial Characteristics of Modern Jews,’ in ‘Jour. Anthr. Inst.,’ vol. xv. pp. 26-28.