[1988] Preyer, ‘Specielle Physiologie des Embryo,’ p. 8.

[1989] Mitchell, ‘Blood-Relationship in Marriage,’ in ‘Memoirs Read before the Anthropological Society of London,’ vol. ii. p. 451.

[1990] Pouchet, loc. cit. p. 107, note *.

[1991] Sebright, loc. cit. pp. 11, et seq.

[1992] Darwin, ‘Cross and Self Fertilisation,’ p. 445.

[1993] Idem, ‘Animals and Plants under Domestication,’ vol. ii. p. 116.

[1994] Idem, ‘Cross and Self Fertilisation,’ p. 457.

[1995] Ibid., p. 465.

[1996] Sebright, loc. cit. p. 12.

[1997] Adam, ‘Consanguinity in Marriage,’ in ‘The Fortnightly Review,’ vol. iii. p. 81.