154 Farm Poultry 



are noted for their useful qualities, were unable 

 to transmit their desirable traits, it might be 

 quite as profitable to breed from the most use- 

 less of animals. In other words, the value of selec- 

 tion depends upon the ability of the parent to 

 impress its own characteristics upon its offspring. 

 That characteristics are transmitted to a certainty, 

 within certain limits, is evident to all. Were this 

 not true there would be no continuity of species, 

 and plants and animals would not " bring forth after 

 their kind." A description of one typical Clydesdale 

 horse will apply to all Clydesdales. 



Variation. It has long been recognized that 

 there is a tendency to vary within certain limits, 

 and that this tendency is always present in all 

 classes of animals, whether wild or domesticated. 

 The fact that wild birds and animals possess suffi- 

 cient individuality to make them readily recognizable 

 by each other is adequate proof that these animals 

 are not precisely alike in all respects. We readily 

 distinguish the differences between individual mem- 

 bers of our herds and flocks, although all members 

 of a flock or herd may have sprung from the mating 

 of two individuals, and therefore have the same 

 lineage. It is more difficult to observe the differ- 

 ences in wild birds and animals, yet such differences 

 exist sufficiently to show that the law of variation is 

 universal and constant in its action. It has been said 

 that "no two animals are exactly alike in all respects." 



