<626 



History of a Grain of Wheat. 



[Oct., 



thickly and are combating with one another to the detriment of 

 the crop. Experiments are in hand for the improvement of the 

 spacing of the wheat seed, and it is claimed that with a suitable 

 machine a perfectly effective seeding can be attained with as 

 little as a bushel to the acre. Even if we could reduce the amount 

 of seed used by one bushed an acre the country would gain 3 per 

 ■cent, on its output of wheat, worth well over £1,000,000 a year 

 at the present time. 



Varieties of Wheat. — Before sowing wheat it is necessary to 

 settle what variety to grow, for hundreds of different sorts of 

 wheat exist — some early, some late, some tall, some short in the 

 straw, some close packed and others open in the ear. We know 

 little about the original wild wheat or wheats, but nowadays 

 varieties of the most diverse kinds in colour, shape, and size 

 exist. In the ordinary way each of these sorts breeds perfectly 

 true, because the flower of the wheat is self -fertilised. Here and 

 there by a rare accident fertilisation does take place in the open 

 field, and it is through these accidents that the multitude of 

 varieties have come into being: As long as the wheat is normally 

 self-fertilised selection can do little to improve it. If, for 

 example, a farmer picks out from year to year the longest ears 

 in the field or the plumpest berries in the sack and sows them 

 he will not find that these characters persist in the next crop, 

 which goes back to the old standard. Selection of this kind has 

 been tried for fifty years in succession, and the wheat at the end 

 could not be distinguished from samples of the first crop that 

 had been preserved. In order to get new varieties there must 

 be deliberate cross-breeding and selection among the progeny. 

 This process was a very haphazard one until latterly, when 

 Mendel showed the mechanism by which selection can be 

 applied so as to pick out among the hybrids the desirable ones 

 that w 7 ill continue to breed true. 



Working on Mendel's principle it is possible to combine in a 

 new variety desirable points possessed by either of the parents ; 

 to combine, for example, a stiff straw in one parent with strong 

 milling qualities possessed by the other parent. Professor Biff en, 

 of Cambridge, has been working for many years on these lines. 

 His first success was " Little Joss," a wheat with a wonderful 

 cropping power on certain soils, because an extra powerof resist- 

 ing rust attacks had been introduced into it through its parentage. 

 Afterwards Professor Biffen turned to the problem of combining 

 the cropping powers of certain English wheats with the high 

 \ milling quality of the wheats, for example, grown in Manitoba. 



