David Starr Jordan 



best or the worst qualities of the parent, or any 

 other quahties; and previous crossings often afFect 

 the results." 



Hybridization differs from ordinary crossing 

 only in degree. A species is only a race which 

 has assumed greater fixity. The purposes and 

 results of crossing within the species and of hybrid- 

 ization of different species are essentially alike. 

 The formation of the new individual by the sexual 

 relation of two parents is in itself a species of 

 crossing, giving each new individual in its degree 

 new traits or new combinations." 



' ' Bees and other insects, as well as the wind, 

 cross plants, but they do not work intelligently, 

 therefore rarely to any advantage economically 

 to man. No mechanic could invent such devices 

 as those which tend to prevent self-crossing in 

 plants. All evolution and improvement are dependent 

 on crossing, therefore nature has produced more 

 wonderful devices for this purpose than for any 

 other." 



"'Mutations, or saltations, are of ten found ; that 



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