LESSON LIV 

 IMPROVEMENT OF PLANTS AND ANIMALS 



Selecting seed. Each fall the successful farmer 

 goes through his cornfield and selects the seed corn 

 from the best plants in the field. He is sure that the 

 seed from stalks with large, well-filled ears will produce 

 a crop of high yield the following summer. When the 

 forester goes through the forest to select seeds from 

 which to grow young trees, he is careful to gather seeds 

 from only healthy and well-formed trees. He knows 

 that the best trees bear seeds that will develop into 

 good trees, and that diseased or otherwise defective 

 trees will produce seeds that will develop into defective 

 trees. The stock farmer will use only the best animals 

 for breeding purposes, for he knows that " like pro- 

 duces like." Heredity is the law of organic life that 

 causes offspring to resemble the parents. Using this 

 law of heredity the farmer selects seeds of the best 

 plants to produce the next crop, and also chooses only 

 the best animals for breeding purposes. This selec- 

 tion of the best plants and animals to produce a new 

 generation is one of the ways in which improvements of 

 domesticated plants and animals have come about. 



Law of variation. While offspring resemble the 

 parents, yet they are not similar to the parents in every 



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