Alfred Henry Sturtevant and crosses between Drosophila melanogaster and Drosophila simulans.

W HEN SEWALL WRIGHT wrote a recommendation for H. J. MULLER in the late 1930s, he described MULLER as perhaps the greatest living geneticist. WRIGHT later expressed this evaluation in conversation on many occasions. But when it came to the relationships among genetics, evolution and systematics, WRIGHT’S clear candidate for honors in the MORGAN group was A. H. STURTEVANT. From his student days on, STURTEVANT had been an avid taxonomist of Drosophila and its close relatives. When WRIGHT first met STURTEVANT during the summer of 191 2 at Cold Spring Harbor, STURTEVANT spent much of his time collecting wild Drosophila (PROVINE 1986). In 191 6 STURTEVANT published a paper on North American Drosophilidae in which he described 23 new species, including D. saltans, virilis, robusta and afinis. STURTEVANT was also keenly interested in speciation and mechanisms of evolution generally. I have argued elsewhere (PROVINE 1981) that he was probably the author of the first document outlining the ambitious “genetics of natural populations” series carried out by THEODOSIUS DOBZHANSKY and his coworkers. One of the first published manifestations of STURTEVANT’S larger interests in the interactions of genetics, systematics and speciation came with his discovery that Drosophila melanogaster was really two species instead of one. STURTEVANT collected melanogaster everywhere he went, especially from his own home town of Kushla, Alabama, and brought them back to the laboratory at Columbia. Males from one Kushla stock were bred by Mr. A. M. BROWN (whom I suppose to be a Columbia undergraduate working in the Fly Room) with females from other mutant laboratory stocks. These matings produced only sterile female offspring. STURTEVANT was fascinated by