WHEAT, OATS, BARLEY 15 



gation and recombination of unit characters in 

 second generation hybrids follows the same rule 

 whether or not the characters show clear dom- 

 inance in the first generation. 



And if we look a little beneath the surface it 

 will appear that there are hundreds or perhaps 

 thousands of unit characters that for one reason 

 or another do not show the phenomena of dom- 

 inance in the first generation and hence are 

 exceedingly difficult to trace, and yet which 

 reappear segregated in new and varied combina- 

 tions in the second generation, thus accounting 

 for the extraordinary diversity of second genera- 

 tion hybrids to which our attention has been 

 called again and again. 



It is interesting to note that Professor Bifferi 

 found such conspicuous conditions as long grain 

 apd short grain to fail to manifest the phenom- 

 ena of dominance and recessiveness. 



Considering that tallness of vine had shown 

 itself to be dominant over shortness of vine in 

 Mendelian peas, it might perhaps have been ex- 

 pected, reasoning from analogy, that long grains 

 of wheat would be dominant to short grains, 



But I have already suggested that it is unwise, 

 to attempt to predict the hereditary tendencies 

 of one plant from observation of another; and in 

 particular it should be said that the stems of 



