362 



Tf 



'34 6 



ROSCOE R. HYDE 



^4.t 



Diagi'am A Expresses the effect on fertility of crossing the extracted truncates 

 B (in which the Truncate male was used as the grandfather) with the original 

 truncates, T. 



Diagram B Expresses the effect on fertility of crossing the extracted truncates 

 A (in which the truncate female was used as the grandmother) with the original 

 truncates, T. 



The flies of table 5 were mated July 21 and the egg count began 

 July 25. The sexes were kept separate for about four days before 

 mating. The results of these crosses are brought together for 

 comparison in diagrams A and B. 



TABLE 5 



Showing the effect on fertility of back-crossing the extracted truncates with the original 

 truncate stock. T = truncate, all from family No. 178. A = truncate extracted 

 from truncate grandmother. B = truncate extracted from truncate grandfather 



COMBINATION 



10 



B9 X TcT No. 178 



A9 X Td^ No. 178 



Bd^ X T9 No. 178 



Acf X T9 No. 178 



Control B9 X B(^ 7 



Control A 9 X Acf J 7 



Control T 9 No. 178 X Tc? No. 178 | 15 

 Control B 9 X Bcf 12 



102 



149 



41 



21 



64 



148 



80 



117 



88 



72 



15 



105 



147 



120 



