116 Segregation of Fecmidity Factors in Drosophila 



and have each segregated from the common pair. No deterioration 

 appears, as F^^ is higher than any preceding generation. 



The individuals from which Table III is prepared were descended 

 from four pairs apparently medium in size, while Table IV shows the 



TABLE III. 



Breeding Record of Line III. {Medium in Size.) 



Pair A Pair B Pair G Pair D 



Fo 81 72 79 84 



r-^ r^n 



36 137 79 65 112 75 81 87 



I I I I 



F^ 31 60 78 142 72 86 34 77 65 121 68 82 87 144 156 138 



i I I I I I I I I I I I II II 



F^ 24 71 74 109 136 150 26 84 71 86 38 141 28 128 146 127 



II I I I I I I 



Fq 19 68 138 68 42 54 28 86 



II I I I I I I 



^7 31 89 161 75 68 26 21 74 



II I I I I I I 



F^ 26 102 124 66 86 34 24 69 



II I I I I I I 



Fq 22 86 152 18 144 32 20 77 



II I I I I I I 



FiQ 25 41 148 24 127 40 23 81 



TABLE IV. 



Breeding Record of Line IV. (^Medium in Vigor.) 



Pair A Pair B Pair G Pair D 



75 80 64 78 



I 1 



78 44 82 87 71 69 74 85 



! 1 



I 



Fi 72 76 41 35 71 139 82 69 30 67 74 77 68 76 78 82 



II II II II II II II II 

 Fs 68 25 78 64 28 72 46 71 70 29 112 56 71 119 134 76 



Fg 29 72 32 62 112 135 74 71 



II I I I ' I I I 



F-! 21 141 34 68 101 120 65 26 



Fs 26 134 29 51 119 124 81 55 



Fq 19 118 25 34 126 74 77 82 



I I I I I I I I 



Fw 22 137 27 25 117 76 74 73 



