[46] On this subject, see Francis Galton. "Natural Inheritance", 1889, p. 132ff. See also G. B. L. Arner, "Consanguineous Marriages", 1908, p. 65ff.; C. B. Davenport, "Heredity in Relation to Eugenics", 1911, p. 124ff. [47] Special Reports, pp. 128, 235, and _passim_. [48] These proportions are further indicated in the succeeding section. [49] Special Reports, p. 135ff. [50] Report, 1908, p. 31. [51] Out of 107 children born to former pupils of the Minnesota School up to 1892, 2, or 1.9 per cent, were deaf. Report, 1892, p. 39. Out of 811 children born to former pupils of the American School up to 1891, 105, or 12.9 per cent, were deaf. Report, 1891, p. 20. [52] The study had been originally planned by Dr. F. H. Wines for the _International Record of Charities and Corrections_. See issue for October, 1888. The work was published by the Volta Bureau. For a discussion of the results, see _Association Review_, ii., 1900, p. 178; Publications of American Statistical Association, vi., 1899, p. 353; _Biometrika_ (London), iv., 1904-5, p. 465. See also charts in current numbers of _Volta Review_. [53] From the total number of marriages, 974 were deducted, being cases concerning the offspring of which no information could be obtained, and also 434 cases where there were no offspring. [54] From p. 134. It has also been computed by Dr. Fay from his data that of 5,455 married deaf persons, 300, or 5.5 per cent, have deaf offspring. _Annals_, lii., 1907, p. 253. [55] The proportions for the general population are hardly over 0.3 per cent and 0.05 per cent respectively. [56] The proportion of the married deaf who are married to deaf partners is found by Dr. Fay to be 72.5 per cent, and of those married to hearing partners, 20 per cent, there being no information for the remaining 7.5 per cent. The census returns, however, give the respective proportions as 51.3 per cent and 48.7 per cent. [57] See Proceedings of National Conference of Charities and Corrections, 1879, p. 214; A. G. Bell, "The Formation of a Deaf Variety of the Human Race", Memoirs, 1883, ii., part 4, p. 177; Proceedings of Conference of Principals, i., 1868, p. 91; v., 1884, p. 205; A. G. Bell, "Marriage, an Address to the Deaf", 1898; Evidence before the Royal Commission on the Deaf, etc., 1892, ii., pp. 74-129; _Annals_, xxix., 1884, pp. 32, 72; xxx., 1885, p. 155; xxxiii., 1888, pp. 37, 206; _Popular Science Monthly_, xvii., 1885, p. 15; _Science_, Aug., 1890, to March, 1891 (xvi., xvii.); _Arena_, xii., 1895, p. 130; _Association Review_, x., 1908, p. 166; _Volta Review_, xiv., 1912, p. 184; Proceedings of Reunion of Alumni of Wisconsin School for the Deaf, vi., 1891, p. 46; National Association of the Deaf, iv., 1893, p. 112; ix., 1910, p. 69; Report of Board of Charities of New York, 1911, i., p. 150.