20 METHODS OF POULTRY MANAGEMENT. 



point is to make the selection of breeders a process of continu- 

 ous picking out the good and culHng the poor throughout the 

 entire growth of the birds. 



Another point of importance is in relation to the size of the 

 breeding stock. It is a nearly universal experience, if line 

 breeding be practised for any particular character, as for exam- 

 ple egg production or feather marking, that unless special at- 

 tention is paid to this point there will tend to be a progressive 

 deterioration in the average size of the birds. This is particu- 

 larly liable to happen when one is breeding for egg production. 

 To counteract this tendency special attention must be paid to 

 the size of the breeding stock, making it a rule never to use as 

 a breeder any bird, whatever the other excellencies may be, 

 which does not attain a certain weight standard set by the 

 breeder. 



What has been said regarding size is only a special case of 

 the general rule of breeding that always the effort in selecting 

 breeders should be towards all-round excellence. Selection for 

 any one character alone — as for example egg production — 

 with an entire disregard of all other characters of the birds 

 will, in comparatively few generations, defeat its own end. It 

 will be found that the stock has deteriorated quite as much in 

 regard to some important qualities as it may have gained in 

 respect to the character for which selection was made. 



While it is not possible here to enter upon an exhaustive dis- 

 cussion of the subject of breeding for egg production a word 

 may be said regarding the results of the Maine Agricultural 

 Experiment Station along this line. From long continued 

 experiments it appears to be conclusively demonstrated that 

 the male bird has a hitherto unsuspected importance in the 

 transmission of high-laying qualities to the progeny. Egg pro- 

 duction, in the Barred Plymouth Rock fowl at least, appears 

 to depend upon two separately inherited physiological factors. 

 Either of these factors when present alone in a bird makes it 

 a poor or mediocre layer. If both factors are present together 

 the bird is a high producer. The novel feature of the case lies 

 in the point that the factor upon which high production depends 

 (i. e., which must be present if the bird is to be a high pro- 

 ducer) is never transmitted in inheritance from a mother to 

 her daughters, but only to her sons. It behaves, in other words 



