31 



The mean fertility of the sires' mates is .0374±. 00642 greater than the mean 

 of the sires ' dams. This is a small but significant difference and indicates that more 

 attention was given to fertility from the female standpoint than from the male stand- 

 point. The standard deviation is almost identical for both groujis of females. A 

 negative coefficient of correlation of .1890 ±.0253(53 appears rather difficult to 

 explain. Jt certainly does indicate that the degree of fertility shown by sire's 

 mother is not an index to the degree of fertility that such a sire will exhibit in his 

 mates — his phenotypical fertilizing ability. This negative correlation may be 

 due to selection of females to be used as breeders with more regard to high fertility 

 in ancestry than is practised in selecting male breeders; or possibly males from the 

 very fertile ancestrj'' were mated to pullets that were lacking in fertility but other- 

 wise desirable. 



Section 9. Relation between the Hatchability of the Sire's Dam and His Phenotypical 



Hatching Ability. 



The question of hatchability may be considered by the same methods used in 

 section 8 in studying fertility. The identical group of birds is again tabulated for 

 hatchabihty in table 9. 



Constants calculated from Table 9. 



Sires' dams' mean hatchabihty 6977±. 005115 



Sires' dams' standard deviation 1929=t .003617 



Sires' mates' mean hatchability 6488±. 005229 



Sires' mates' standard deviation 1972±. 003698 



Coefficient of correlation ....... .1579± .025856 



