ON THE SMALL GRAINS 



is no danger of unintended cross-poUenizing — in 

 other words, the plants of the second and subse- 

 quent generations will normally inbreed and thus 

 reveal hereditary potentialities without further 

 attention from the experimenter; whereas with 

 most other plants of another habit it is necessary 

 to guard constantly against cross-fertilization, 

 Mendelian Clues 



The essential facts of Mendelian discovery with 

 regard to "unit" characters and their grouping 

 into pairs, in which one character is dominant and 

 one recessive, have been more than once called to 

 our attention and have been illustrated again and 

 again with instances drawn from my own plant 

 experiments. 



The cases of the black and white blackberries, 

 the thorny and thornless blackberry, and of stone- 

 bearing and stoneless plums, among others, will 

 be recalled. 



But we have also observed cases in which the 

 characters of two parents seemed to be blended in 

 the offspring, there being no clear dominance of 

 one character over another. Such was the case, 

 for example, with the Sunberry, the Primus berry, 

 and the Plumcot. 



Now it is peculiarly interesting to note, in the 

 light of our experiments with various fruits and 

 flowers of widely different orders, that Professor 



[57] 



