ANGIOSPERMS 447 



and wheat just as we have heard of thoroughbred horses. 

 Scientific farmers recognize the superior value of seed corn 

 whose ancestors through many seasons have shown a high 

 record of bushels per acre. That, rather than the superficial 

 appearance of an ear, is the real test of seed corn as to its 

 probable crop-producing capacity. 



The scientific breeding of animals and decorative plants 

 has a much longer history than the scientific breeding of 

 agricultural plants. You know of the many kinds of dogs, 

 horses, pigeons, and pigs and of the varieties of cultivated 

 flowers whose existence is due chiefly to the control by man 

 of the operations of nature. By similar methods man 

 seeks now to obtain kinds or strains of crop plants which 

 will be even better than those kinds which have resulted 

 from the less scientific agriculture of the past. (See pages 

 15, 16, and 220.) 



Another great fact of life which lies at the basis of breed- 

 ing is the fact that the sex process of reproduction neces- 

 sarily results in an individual which, in combining the traits 

 of both its parents, is necessarily different from either. 

 The more dissimilar the parents are, the greater is the like- 

 lihood of striking variation from both parents on the part 

 of the progeny. The crossing of different species is called 

 hybridization (see page 305), and it is by this means that 

 the most striking forms of cultivated plants and animals 

 have been obtained. Luther Burbank of California is the 

 best-known plant breeder in America, and it is chiefly by 

 hybridization that his most surprising results have been 

 obtained. People have exaggerated his work as to its value 

 in agriculture, but it indicates what results may be obtained 

 by the skilled breeder. Scientific plant breeders in govern- 

 ment and state employ are now at work, with many evi- 



