Linkage of rudimentary, forked, and bar 62 Shifted 63 Linkage of shifted and vermilion 63 Linkage of shifted, vermilion, and bar 64 Lethals _sa_ and _sb_ 64 Bar 66 Notch 66 Depressed 67 Linkage of depressed and bar 67 Linkage of cherry, depressed, and vermilion 68 Club 69 Genotypic club 70 Linkage of club and vermilion 70 Linkage of yellow, club, and vermilion 70 Linkage of cherry, club, and vermilion 72 Green 73 Chrome 74 Lethal 3 74 Lethal 3_a_ 75 Lethal 1_b_ 76 Facet 76 Linkage of facet, vermilion, and sable 77 Linkage of eosin, facet, and vermilion 78 Lethal _sc_ 79 Lethal _sd_ 79 Furrowed 80 Additional data for yellow, white, vermilion, and miniature 80 New data contributed by A. H. Sturtevant and H. J. Muller 82 Summary of the previously determined cross-over values 83 Summary of all data upon linkage of gens in chromosome I. 84 BIBLIOGRAPHY. 86 * * * * * {5} PART I. INTRODUCTORY. MENDEL'S LAW OF SEGREGATION.