William Harvey, Anatomical Excercises on the Generation of Animals, trans. Robert Willis, London, 1847, p. 462. Ibid., pp. 336-339. Works of William Harvey, trans. Robert Willis, London, 1847, pp. lxx-lxxi. Harvey, op. cit., pp. 462-463. Ibid., p. 457. F. J. Cole, Early Theories of Sexual Generation, Oxford, 1930, p. 140. Thomas Browne, The Works, ed. Geoffrey Keynes, Chicago, 1964, I, 261-262.