254 HEREDITY AND VARIATION 



breeders select the forms having the characters they wish to per- 

 petuate and breed them together. This method used by plant 

 and animal breeders is known as selection. 



Selective Planting. — By selective planting we mean choosing 

 the best plants and planting the seed from these plants with a view of 

 improving the yield. In doing this we must not necessarily select 

 the most perfect fruits or grains, but must select seeds from the 

 test plants. A wheat plant should be selected not from its yield 

 alone, but from its ability to stand disease and other unfavorable 

 conditions. In 1862 a Mr. Fultz, of Pennsylvania, found three 

 heads of beardless or bald wheat while passing through a large 

 field of bearded wheat. These were probably mutants which had 

 lost the chaff surrounding the kernel. Mr. Fultz picked them out, 

 sowed. them by themselves, and produced a quantity of wheat now 

 known favorably all over the world as the Fultz wheat. In select- 

 ing wheat, for example, we might breed for a number of different 

 characters, such as more starch, or more protein in the grain, a 

 larger yield per acre, ability to stand cold or drought or to resist 

 plant disease. Each of these characters would have to be sought 

 for separately and could only be obtained after long and careful 

 breeding. The work of Mendel (see page 257) when applied to 

 plant breeding will greatly shorten the time required to produce 

 better plants of a given kind. By careful seed selection, some 

 Western farmers have increased their wheat production by 25 

 per cent. This, if kept up all over the United States, would mean 

 over $100,000,000 a year in the pockets of the farmers. 



Hybridizing. — We have already seen that pollen from one 

 flower may be carried to another of the same species, thus produc- 

 ing seeds. If pollen from one plant be placed on the pistil of an- 

 other of an allied species or variety, fertilization may take place 

 and new plants be eventually produced from the seeds. This 

 process is known as hybridizing, and the plants produced by this 

 process known as hybrids. 



Hybrids are extremely variable, rarely breed from seeds, and often 

 are apparently quite unlike either parent plant. They must be 

 grown for several years, and all plants that do not resemble the 

 desired variety must be killed off, if we expect to produce a hybrid 



