E. J. Allen and E. W. Sexton 359 



(c) Hybrid Black male x Pure Red female ; 5 pairs. 



One family (Exp. IX) gave 228 unspotted and 50 spotted ; a percentage of 18. 



{d) Pure Red male x Hybrid Black female ; 2 pairs. 



One family (Exp. X) gave 439 unspotted and 8 spotted ; a percentage of 1*8. 

 The other gave 123 unspotted and 16 spotted ; a percentage of 11-5. 



(e) Pure Red male x Pure Red female ; 5 pairs. 

 One family gave 148 unspotted, and 7 spotted ; a percentage of 4 "5. 



Another (Exp. V) gave 173 „ „ 9 ,, „ „ 4-9. 



Another gave 281 „ „ 13 „ „ „ 4-4. 



Another (Exp. IX 6) gave 76 „ „ 6 „ „ „ 73. 



In Experiment IX b the Red male (from d) which had given the 

 lowest percentage of spotted, l'8 7o, was mated the Red female (from c) 

 which had given the highest, 18 %. 



For the F2 generation, we mated the Fi young Reds to see (1 ) if the 

 homozygous for colour would give any different results from the hetero- 

 zygous, and (2) if a mating giving a high percentage of spotted in the 

 -Fi generation would continue to give it in the F2. 



The Experiment IX, which had given the highest percentage, 18 %, 

 was taken and nine matings of F^ unspotted Reds were made ; results 

 as follows : — 



One family gave 306 unspotted Red and 28 spotted ; a percentage of 8-3. 

 Another family gave 287 ,, ,, 5 ,, ,, ,, 1-7. 



Another „ 253 



Another ,, 150 



Another ,, 164 



6 ,, „ ,, 2"3. 



4 „ „ „ 2-6. 



10 „ „ ,. 5-7. 



The percentage of spotted offspring from each of the nine pairs was 

 low, var3ring from 8*3 °/^ to or 1 %. 



This result may be compared with the Fi matings of unspotted Reds 

 from the Experiment X^ which had given the lowest percentage, 1"8 7o- 

 The percentage varied from 4*8 °/^ to °/^. The largest family gave 

 426 unspotted and 6 spotted, a percentage of 1*4. 



It may also be compared with the Fi matings from Experiment V 

 (from e) which gave a mean percentage 4*9. 



One pair gave 137 unspotted and 5 spotted ; a percentage of 3*5. 



Another pair (1) gave 146 ,, 5 „ ,, „ 3'3. 



Another pair (2) „ 126 „ 23 „ „ „ 16-4. 



1 The largest families from the heterozygous matings of the Fi young from this 

 same experiment were : 



Hybrid x Red One family of 657 unspotted and 11 spotted ; a percentage of 1-6. 

 Hybrid X Hybrid „ „ 104 „ „ 3 „ „ 2-8, 



