1. Penrose , A Clinical and Genetic Study, 1938 (op. cit. 39), p. 10 and chapter 7
2. Hogben , Nature of Living Matter, 1930 (op. cit. 39), p. 208
3. Hogben , Nature and Nurture, 1933 (op. cit. 39), p. 31.
4. Kevles , op. cit. (4), p. 344, note 5.
5. Fisher , Eugenics Rev., 1924 (op. cit. 39), pp. 114–115