No. 578] DROSOPHILA AMPELOPHILA 113 



TABLE XV 



F a of a Cross Bed by Pink in Which the Barents Were BIY and al 

 (Table XII) the Average Daily Productivity of Which 

 Was l and 22, Respectively 

 A. PinTc 2 (Productivity I Per Day) X Bed J (Productivity 22) 



7 I 17 198 j 220 58 ^ 418 141 i 559 3.00 



8 1 17 1 174 I 212 ! 62 I 62 386 \ 124 51 ' 3.10 



Total number produced by 8 pairs | 5,665 | 1,620 j 7,285 | 



Average proportion, 3.50 : 1 



B. Bed ? (Productivity 22 Per Day) X Pink <J (Productivity 1) 







— » 









I 



II 

 in 



VII 

 VIII 



31 

 31 

 28 

 28 



264 

 353 

 430 

 427 

 486 

 573 

 505 

 502 



262 

 350 

 403 



471 



568 

 505 

 501 



97 



139 

 134 



85 703 165 

 112 833 209 

 128 847 239 

 147 957 269 

 154 1,141 293 

 127 1,010 243 

 140 1 1,003 274 



714 | 2.80 : 1 



L226 3.60 : 1 

 1,434 | 3.90 : 1 

 1,253 4.15 : 1 

 1,277 | 3.66 : 1 



Total produced by 8 pairs 7.020 I.s*> V.HK) 



Of the 16 pairs of this cross only one gave less than 3 : 1. 

 In the remaining 15, the proportion was, in each case, 

 considerably higher than 3:1. It will be noted that of 

 all 16 pairs that one was the least fertile. This would 

 indicate, on the hypothesis suggested, that the gamete 

 containing the "red" factor did not have relatively as 

 high a potential of fertility as did the parent which pro- 

 duced it. 



A comparison of Tables XIV and XV shows that we 

 have two distinct groups : one in which the extracted pink 

 exceed the expectation, and one in which they fall behind 



