326 



MUTATIONS IN EYE-COLOR OF DROSOPHILA. 



The expectation is 3 Reds to 1 Pink. The results vary from 6.5 to 1 to 2.5 

 to 1, the sum total giving a ratio of 3.5 to 1, which closely approximates to the 

 results of the mass culture. 



The reciprocal cross, recorded in pairs, is given in the next table. The 

 ratio ranges from 5.8 to 1, to 1.8 to 1. The average proportion of Red to Pink 



3.84 to 1 



Bottle. 



I 



II 



III 



IV 



V 



VI 



VII 



VIII 



IX 



X 



XI 



XII 



XIII 



XIV 



XV 



XVI 



XVII 



XVIII 



XXII 



XXIII 



XXIV 



XXV 



XXVI 



Bed. 



57 

 62 



69 

 25 

 58 

 41 

 107 

 83 

 49 

 10 

 42 

 21 

 51 

 83 

 94 

 72 

 50 

 83 

 53 

 78 

 56 

 52 

 19 

 8 

 43 

 19 



9 



Pink 



17 

 15 

 17 

 7 

 13 

 14 



29 

 14 

 14 



2 

 17 

 15 

 10 

 17 

 19 

 27 

 10 

 22 



7 



14 

 16 



19 

 5 



1 



15 

 4 



1,385 



360 



out of Pink 9 X Red cf . 



Bed. 



64 



54 



75 

 39 

 41 

 32 

 72 

 71 

 59 

 14 



45 

 30 

 38 

 80 

 84 

 54 

 29 

 45 

 53 

 61 

 55 

 41 

 21 

 3 

 50 

 14 



c? 



Pink 



19 

 21 

 17 



4 

 20 

 12 

 42 

 25 

 15 



4 

 10 

 14 



7 



16 



23 



15 



5 



10 



12 



16 



12 



6 



6 



1 



9 



4 



Total. 



Bed. 



121 

 116 



144 



64 



99 



73 

 179 

 154 

 108 



24 



87 



51 



89 

 163 

 178 

 126 



79 

 128 

 106 ♦ 

 139 

 111 



93 



40 



11 



93 



33 



Pink 



36 

 36 

 34 

 11 

 33 

 26 

 71 

 39 

 29 



6 

 27 

 29 

 17 

 33 

 42 

 42 

 15 

 32 

 19 

 30 

 28 

 25 

 11 



2 

 24 



8 



Grand Total 



157 

 152 

 178 



75 

 132 



99 

 250 

 193 

 137 



30 

 114 



80 

 106 



196 

 220 

 168 

 94 

 160 

 125 

 169 

 139 

 118 



51 

 13 



117 

 41 



Proportion of 

 Bed to Pink. 



1,224 



345 



2,609 



705 



3,314 



3.4 

 3.2 

 4.2 



5.8 



3 



2.8 



2.5 

 4 



3.7 



4 



3.2 



1.8 



5.2 



5 



4.2 



3.2 



5.3 

 4.0 

 5.5 

 4.6 

 4 



3.7 



4 



5 



4 



4 



The four back crosses between the Fi red females and males were made, and 

 are recorded in the four following tables. In each case equality in four classes 

 is expected. There can be little doubt that the results accord with the expec- 

 tations, although the Reds once more run ahead of the Pinks. 



Red 9 (out ofR 9 X P <?) X Pink 



Bottle. 



A 

 B 

 C 



Total 



1 



? 



& 



To 



Bed. 



Pink. 



Bed. | 



Pink. 



Bed. 



82 



98 

 86 



266 



68 

 62 

 63 



60 

 83 

 71 



51 

 80 

 71 



202 



142 

 181 

 157 



193 



214 



480 



Pink. 



119 

 142 

 134 



Grand Total 



261 

 323 

 291 



875 



Average proportion 



Proportion of 

 Red to Pink. 



1.3:1 

 1.2:1 

 1.2 : 1 



1.2:1 



« 



