ORIGIN AND IMPROVEMENT OF FRUIT 315 



the individual choosing of forms that meet the ideal of the 

 person conducting the work and has been unconsciously prac- 

 ticed by man in all stages of civilization since the time he 

 began to cultivate plants and to domesticate animals. With 

 plants commonly grown from seed, such as grains and vege- 

 tables, this method of improvement has found wide usage 

 and has been claimed by some to be the only means neces- 

 sary. This belief is founded on the principle of variation, 

 and on the fact that all possible genetic combinations may 

 occur in natural crosses. With fruit-trees, however, selection 

 as a method of plant improvement has been given less at- 

 tention, as fruits are reproduced asexually. Every Baldwin 

 apple or Elberta peach tree is a part of the original tree 

 which was a chance seedling. 



Such being the case, there remain but two methods of 

 selection with fruits: namely, of bud sports or mutations, 

 and of new forms that have come from seed. The latter 

 may properly be subdivided into three phases: (1) a choice 

 of trees that are chance seedlings, in the origin of which 

 man has played no part; (2) a selection of the superior trees 

 from a miscellaneous lot of seeds sown; and (3) a selection 

 of trees which result from flowers crossed or hybridized by 

 the grower. 



First, it must be recognized that man has nothing what- 

 ever to do with the occurrence of the superior individual or 

 variety under the first two methods of selection, but rather 

 he "finds" it. On the other hand, through crossing or 

 hybridizing, new forms may be secured by the combination 

 of desirable characters within one plant, or by "breaking the 

 type" or causing the original plant to vary. 



The chief methods of selection commonly used in im- 

 proving plants are: (1) mass; (2) line; and (3) clonal selec- 

 tion. The method will of necessity depend on the object in 

 view and the nature of the material used in breeding. 



