Inbreeding 



193 



the mother and more than other A-mothers. Their productive- 

 ness is nearly the same as that of the M- and N-series. In other 

 words, the male has transmitted the greater productiveness of his 



Average 

 Ko.Young 



.450 



400 



350 



300 



250 



200 



150 



'100 



50 







Generation l 3 

 Qct'.190a 





9 11 13 16 17 19 21 1 23 25 28 

 June 1904 OctOSM Jcn.1905Apr.1905 



FlG. 19. Curve of productiveness of fertile pairs of M- and N-series of Pomace 

 fly. (After Castle.) 



| race to his offspring. Complete sterility, however, appeared 

 more often among the daughters than in the M- and N-series; 

 and in this respect the influence of the A- series is observed. 

 Conversely, if a female of the M- or N-series is mated with a 



