The Law of Variation 



143 



looks closely for those individuals that show the 

 greatest tendency to vary. These individuals he 

 selects for breeding stock. He finds that their 

 young vary considerably. They do not closely 

 resemble each other, nor do they closely resemble 

 their parents. If an abundance of good food and 

 congenial surroundings be provided, he may ex- 

 pect, in the course of a few generations, that some 



Fig. 51. An inclosed scratching shed, an excellent plan 

 Rhode Island Agricultural Experiment Station. 



individuals will show a marked tendency to vary 

 in the direction of improvement. By judicious 

 mating, some or all of the desired improvements 

 may be transmitted and rendered permanent. 

 The improvement of breeds consists essentially in 

 fixing the desired variations. 



Poultrymen usually look to the male for the 

 greatest tendency to vary.* Consequently in many 



* "Heredity," by Wm. H. Brooks. 



