" BLENDING INHEKITANCE 



in maize, seemingly blending is really segre- 

 gating inheritance, but with entire absence of 

 dominance, and it seems probable that the same 

 will be found to be true among rabbits and 

 other mammals; failure to observe it hitherto 

 is probably due to the fact that the factors 

 concerned are numerous. For the greater the 

 number of factors concerned, the more nearly 

 will the result obtained approximate a com- 

 plete and permanent blend. As the number 

 of factors approaches infinity, the result will 

 become identical with a permanent blend. 



Theoretically it is important to know whether 

 segregating units are involved in inheritance 

 which we call blending; practically it does not 

 matter much, since if these units are only as 

 numerous as six or eight it will be practically 

 impossible to undo the effects of a cross and to 

 recover again the conditions obtaining previous 

 to the cross. The great majority of the offspring 

 both in the first and in subsequent generations 

 following the cross will be strictly intermediate 

 between the conditions crossed whether several 

 units, an infinite number of units, or no units 

 at all are involved. 



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