1032 Recent Research in Egg Production. [Feb., 



frequently resorted to by commercial poultrymen in order to 

 increase the vigour of the strain, it is remarkable that practi- 

 cally no experiments have been made to determine the effect 

 of in-breeding and crossing on the fecundity, fertility and 

 size of the bird. Research on these lines might lead to valuable 

 conclusions. 



Elimination of Cockerels. — Punnett^ 7 ) has shown that 

 breeders may eliminate at once all cocks from their hatch of 

 chicks and rear only pullets, provided certain colour crosses are 

 made. By mating hens of some breeds with cocks of a different 

 colour the male chicks can be picked out as soon as they are 

 hatched and disposed of, thus ensuring that all accom- 

 modation is available for rearing pullets. If a black cock 

 is used with barred Plymouth Rock hens, all the male chicks 

 are barred and all the females are black. The male barred 

 chicks can then easily be identified at hatching by the white 

 patches of down on the head and rump. 



A silver coloured hen transmits silver to her sons and gold 

 to her daughters in the same way. Silver and Gold Laced 

 Wyandottes are examples of this, as also are breeds such as 

 Light Dorkings (silver) when crossed with Brown Leghorns 

 (gold) . 



In conclusion it must be emphasized that many of the obser- 

 vations and experiments quoted above have been made only on 

 a small scale and that many, before they are generally accepted, 

 should be repeated under the conditions existing in this country. 



(47) Journal Bd. of Agrfc., Vol. XXV., Feb., 1919. 



