Improving Plants and Seeds 139 



205. "Natural Selection." The original wild species 

 owe their form and habits to the continuous selections 

 which wild nature makes. Wild plants must grow in 

 competition with other plants and struggle with them 

 for the conditions necessary for growth and the preser- 

 vation of their seeds. The size, form and character of 

 the leaves, stems, flowers, fruits and seeds, are all im- 

 portant features in the struggles for nature's favors. 



206. No Improvement Without Variation. No two 

 plants are exactly alike. The offspring from the same 

 individual are not alike. This is the fact of " variation." 

 In some forms the variations are more obvious than in 

 others. As a rule, variations in wild plants are less fre- 

 quent than in cultivated forms. Variations may be 

 desirable or undesirable and progress comes from propa- 

 gating only the best selections. Improvements could not 

 be made if all individuals were alike. 



207. Variations Are Not Permanent. The Concord 

 grape is a variation of the wild fox grape of Massachu- 

 setts, discovered by E. W. Bull about 1850. It has 

 been propagated by division ever since and is still the 

 same grape, because our Concord grape-vines of today 

 are only parts of the original plant. However, when the 

 seed of Concord grapes are grown, we get the original 

 wild fox grapes. Many such seedlings have been grown, 

 but none have yet been secured that are the same as the 

 parent vine, although some of them are very nearly like 

 it. DeVries had a variety of corn, the ears of which had 

 eight to twenty-two rows of grains. The average num- 

 ber of rows was between twelve and fourteen. He 

 planted an ear having sixteen rows and found the aver- 

 age in the crop to be fifteen rows per ear. He then planted 

 some ears having twenty rows and continued this for 



