THE MENDELIAN CLUE 237 
and how undesirable qualities may be slipped off, 
and never was it more necessary than now to put 
all our available science into the art of cultivation 
and breeding. The average yield of wheat in 
Britain is about thirty-two bushels to the acre. 
Professor Wilson tells us that it might be raised to 
forty or even fifty. ‘For every day by which the 
life of a variety of wheat is shortened between seed- 
time and harvest, the wheat-growing area in Canada 
reaches fifty or sixty miles farther northwards.” 
The work done in Denmark shows how the wealth 
of our country, so far as it proceeds from dairy 
cattle, might be very nearly doubled. These are 
two instances out of many which might be cited to 
illustrate the practical value of Mendelism—and it 
is only beginning. 
