In Pursuit of the Gene

326 ¨ NOTES TO PAGES 190–192
multifactor inheritance (“Some Reminiscences of H. J. Muller,” autumn 1965, Madison,
Wisconsin, notes taken by Charlotte Auerbach, Muller Collection). When
Muller finally met William Bateson in New York in 1921, he was dismissive of
Bateson and described him as “old-school” and “unjustifiably famous” (H. J. Muller
to Miss Jessie Jacobs, Dec. 26, 1921, and June 28, 1922, Muller Collection). But Muller
had failed to appreciate that it was Bateson, via his disciple and colleague Robert
Lock, who had won him over to the study of genetics in the first place.
16. H. J. Muller, “Obituary Notices: Dr. Calvin B. Bridges,” Nature 143 (1939):
191–192.
17. R. C. Punnett, Mendelism (Cambridge: Macmillan and Bowes, 1905). The story
of Sturtevant’s early life is given in “Biographical Notes” written by Sturtevant
himself (Box 7, Sturtevant Papers, Millikan Library Collection, Archives, California
Institute of Technology). See also E. B. Lewis “Remembering Sturtevant,” Genetics
141 (1995): 1227–30.
18. In the first place, Sturtevant proposed that coat color is determined by a dominant
factor for black pigment, which he called the Hurst factor and denoted as H.
The absence of black (the recessive form), he denoted as h. In addition, he introduced
a new gene, a second factor, which he called B for bay, and he denoted its recessive
form (which he believed, following Bateson, to be an absence) as b. Horses
homozygous for the absence of black—of genotype hh—were always chestnut regardless
of the bay gene. Bays, on the other hand, contained at least one copy of
the dominant Hurst factor (H) and one copy of the dominant bay gene (B). Browns
likewise contained the dominant Hurst gene, but might or might not contain the
dominant bay factor, and pure blacks were always of the form HHbb. With the introduction
of two further gene pairs, G/g and R/r, Sturtevant accounted for the
complete range of coat colors—chestnut, bay, brown, black, grey, and roan. (A. H.
Sturtevant, “On the Inheritance of Coat Color in the American Harness Horse,” Biological
Bulletin 19 [1910]: 204–216.)
19. Muller describes T. H. Morgan’s reaction in a lecture entitled “An Episode in
Science” he gave at the Biological Laboratory of the Brooklyn Institute, Cold
Spring Harbor, on July 25, 1921 (Muller MSS).
20. T. H. Morgan, “Personal Recollections of Calvin B. Bridges,” Journal of Heredity
30 (1939): 355.
21. T. H. Morgan, “Random Segregation versus Coupling in Mendelian Inheritance,”
Science 34 (1911): 384.
22. A. H. Sturtevant says the idea came to him in the latter half of 1911
(Sturtevant, A History of Genetics, 47).