1. Brooks, W. K., 1883, The Law of Heredity, Murphy Press, Baltimore, pp. 32–33.
2. Weismann, A., 1893, The Germ-Plasm: A Theory of Heredity, Walter Scott, London (trans. by W. N. Parker and H. Ronnfeld).
3. Gilbert, S. F., 1978, The embryological origins of the gene theory, J. Hist. Biol. 11: 307–351.
4. Driesch, H., and Morgan, T. H., 1895–1896, Zur Analysis der ersten Entwickelungstadien des Ctenophoreneis I. Von der Entwickelungeinzeluer Ctenophorenblastomeren, Arch Entwick. 2:204–215. Experiments analyzed in Morgan, T. H., 1897, The Frog’s Egg, Macmillan, New York, p. 135.
5. Stevens, N. M., 1905, Studies in spermatogenesis with especial reference to “The Accessory Chromosome,” Carnegie Institution, Washington, DC; and Wilson, E. B., The chromosomes in relation to the determination of sex in insects, Science 22:501–502. These papers are discussed hi Ref. (3).