20 LUTHER BURBANK 



To ascertain this it was necessary only to plant 

 the grains showing the desired quality in plots by 

 themselves. 



The individuals that produced only hard- 

 grained offspring in the next generation were 

 thus shown to be pure dominants for that 

 quality. They constituted a fixed race and 

 could be depended upon to breed absolutely 

 true. 



Thus the clear recognition of the qualities of 

 Mendelian segregation, as applied to the differ- 

 ent pairs of unit characters representing respec- 

 tively desirable and undesirable qualities of the 

 wheat, enabled Professor Biffen to produce in 

 the third generation a fixed race of wheat having 

 the desired qualities of grain and a plant stem 

 that is immune to the yellow rust. 



The seeds of this new variety being multiplied 

 as rapidly as possible, a wheat was produced that 

 promises to be of enormous importance to the 

 grain growers of England. 



It is obvious that a similar line of experiment 

 should enable the plant developers of other coun- 

 tries to produce new varieties of wheat that will 

 be immune to the various rusts, and thus to 

 rid the agriculturist of one of the pests that 

 of all others has hitherto rendered his calling 

 precarious. 



