502 



PLANT BREEDING 



and others with pollen of different species of plum. All of the 

 seeds obtained from the various crosses should be planted, and the 

 seedlings which are produced by them should be examined, and 

 retained or destroyed according to their apparent value. To the 

 experienced plant breeder the appearance of the seedling trees, 

 long before they are old enough to blossom, indicates so much as 



to the nature of their fruit that many 

 varieties can be discarded as soon 

 as the young plants have developed 

 well-grown shoots. The distinctive 

 work of hybridizing is to secure 

 parent plants better than any which 

 exist in the foundation species or 

 varieties. The work of choosing a 

 large number of the most promising 

 hybrid plants and of testing their 



FIG. 375. A plum blossom pre- breeding power, so that only the 

 pared for hybridizing | )loodj go to speak? o f tlie yery best 



A, unopened blossom cut round ma y be retained, is the same as 



just below the insertion of the , , . , , . . n 



stamens, to remove the latter; breeding by selection mentioned 

 B, lengthwise section of a fully above. In the occasional hybrid 



opened blossom, showing the , ., , 



level s at which the cutting plant, possibly one out of ten thou- 

 should be done sand, are combined the best in the 



two parents, or possibly, as some believe, newly created char- 

 acters may arise. 



481. Some results in breeding by selection. To give an 

 account of the results of selection as applied to cultivated plants 

 would be to write a history of the variations and improvements 

 in all our ornamental and useful plants under cultivation. In 

 this place it must suffice to give a very few illustrations of the 

 kind and amount of improvement brought about by such selec- 

 tion as is outlined in Sec. 479. 



482. Selection among apples. Much of the improvement 

 in apples was brought about before the literature of plant breed- 

 ing began. It is not certainly known where the cultivated apple 



