138 POULTRY PRODUCTION 



Fecundity. — Fecundity, the supreme object of breeding, 

 for which vigor and hatching power are the foundation, is 

 the point of selection which until recently has been least 

 understood. Considerable light has been thrown on the 

 subject by Doctor Pearl,^ who seems to have demon- 

 strated beyond reasonable doubt that high fecundity and 

 the ability to transmit high fecundity to female offspring 

 are two very different matters. This is somewhat 

 comparable to the fact that sires of speed among horses are 

 not themselves necessarily great performers with regard to 

 speed. On the other hand, a stallion may be very fast 

 and yet fail to sire colts that are speedy. Speed and the 

 ability to transmit speed are separate characters. Just so 

 the ability to lay a large number of eggs in a given period 

 and the ability to beget offspring that are highly fecund do 

 not necessarily go together. 



Pearl has further shown that females can inherit the 

 power of high production from the male parent only. The 

 most familiar example of this type of inheritance in poultry 

 and one which may aid in understanding the way in which 

 the inheritance of fecundity is limited, is found in the case 

 of the Barred Plymouth Rock. It is a matter of common 

 observation that the Plymouth Rock males are always of a 

 lighter shade than the females. This comes about through 

 the fact that the females inherit the light bars from their 

 sires only and never from their dams, whereas the males 

 usually inherit light barring from both sire and dam, thereby 

 receiving a double dose of the light barring. 



' Rogers, Cornell Countrjrman, vol. iz, No. 3. 

 ' Maine Bulletin No. 205. 



