146 . MENDELISM CHAP. 



a high glutinous content could not be grown in 

 the English climate, and undoubtedly most of the 

 hard varieties imported for trial deteriorated greatly 

 in a very short time. Professor Biffen managed to 

 obtain a hard wheat which kept its qualities when, 

 grown in England. But in spite of the superior 

 quality of its grain from the baker's point of view, 

 its cropping capacity was too low for it to be grown 

 profitably in competition with English wheats. 

 Like the latter, it was also subject to rust. Among 

 the many varieties which Professor Biffen collected 

 and grew for observation he managed to find one 

 which was completely immune to the attacks of the 

 rust fungus, though in other respects it had no 

 desirable quality to recommend it. Now as the 

 result of an elaborate series of investigations, he was 

 able to show that the qualities of heavy cropping 

 capacity, " hardness " of grain, and immunity to rust 

 can all be expressed in terms of Mendelian factors. 

 Having once analysed his material the rest was 

 comparatively simple, and in a few years he has 

 been able to build up a strain of wheat which com- 

 bines the cropping capacity of the best English 

 varieties with the hardness of the foreign kinds, and 

 at the same time is completely immune to rust. 

 This wheat has already been shown to keep its 

 qualities unchanged for several years, and there is 

 little doubt that when it comes to be grown in 

 quantity it will exert an appreciable influence on 

 wheat-growing in Great Britain. 



It may be objected that it is often with small 

 differences rather than with the larger and more 

 striking ones that the breeder is mainly concerned. 



