[1648] Darwin, ‘Animals and Plants under Domestication,’ vol. ii. pp. 102, et seq.
[1649] Darwin, ‘The Descent of Man,’ vol. ii. p. 381.
[1650] de Quatrefages, loc. cit. p. 273.
[1651] Topinard, ‘Anthropology,’ p. 371.
[1652] Nansen, loc. cit. vol. ii. p. 238.
[1653] Topinard, p. 372.
[1654] Périer, in ‘Mém. Soc. d’Anthr.,’ vol. ii. p. 340.
[1655] Topinard, loc. cit. p. 383.
[1656] Prichard, loc. cit. vol. i. p. 149.
[1657] Godron, loc. cit. vol. ii. p. 360, note 2.