36 PROGRESSIVE POULTRY CULTURE 



in a pod, yet no two birds are ever exactly alike. That 

 is one thing that makes them interesting. In each 

 there is a somewhat different arrangement of the domi- 

 nant and latent qualities so that we recognize individ- 

 uality. 



If the parent birds produced chickens which at 

 maturity, would be just like themselves and all alike 

 among themselves there would be an end of improve- 

 ment. Fortunately for the enterprising and progressive 

 poultry breeder, all the birds of one breed; or even of 

 one family are not cast in exactly the same mold. Al- 

 though the general characteristics of the parents are 

 inherited yet there are often decided variations in the 

 offspring. Some of these are explainable by Atavism 

 but others and especially such as indicate improvement 

 in qualities of use to the poultryman, are brought about 

 by conditions of Environment and Exercise which are 

 largely within the control of the breeder. 



When animals are brought into surroundings dif- 

 fering from those of their previous environment, they 

 sometimes find themselves not fully adapted to the new 

 conditions. If changes in themselves are necessary in 

 order to exist under the circumstances, they yield or 

 try to yield to the influences. Variations result in their 

 organisms or in their offspring which better adapt them 

 to live under the changed conditions. 



Domestic birds yield more readily than wild birds 

 to the influences tending to cause variation. 



The causes of variations more or less within the 

 controlling power of the poultryman include those of 

 climate, nourishment and exercise. 



By a careful selection and combination of influ- 

 ences steadily continued in their application, the birds, 

 in some cases and after a time, are induced to vary. 

 By keeping the conditions constant long enough the 

 variation becomes a fixed characteristic of individuals. 

 Then by selection of the individuals which show the 

 desired variation most decidedly, and breeding from 

 them, certain variations at least appear to become trans- 

 missible by inheritance. 



