Scientific Aspects of Luther Bu? bank's Work 



* 'Crossing gives the raiser of new plants the 

 only means of uniting the best qualities of each, 

 but just as often the worst qualities of each are 

 combined and transmitted, so that to be of any 

 value it must be followed by rigid and persistent 

 selection, and in crossing, as in budding and graft- 

 ing, the afhnities can only be demonstrated by 

 actual test. 



''All wild plants of any species are under almost 

 identical environments, having their energies taxed 

 to the utmost in the fierce struggle for existence. 

 Any great variation under such circumstances is 

 not likely to occur, and is much more likely to be 

 stamped out at once by its struggling competitors, 

 unless the variation should be of special use in 

 competition, in which case it wdll survive, and 

 all others may be supplanted by it. Thus we see 

 how new species are often produced by nature, 

 but this is not her only mode. Crosses and hybrids 

 are very often found growing wild where two 

 somewhat similar species grow contiguous, and if 

 the combination happens to be a useful one, as it 



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