74 Breeding Plants and Animals. 



floret is young and the anthers still greenish in color,, 

 though nearly ready to turn yellow, and as they ripen 

 to break open and shed their pollen on the stigma. 

 After emasculating the head of wheat it is covered with 

 tissue paper, gently tied on, to prevent the introduction 

 of foreign pollen. In 24 to 48 hours, when the stigma 

 has become receptive, as shown by the opening of neigh- 

 boring florets of the same age, the covering is removed 

 and pollen from anthers taken from strong plants in 

 the variety used as the male parent is dusted on. The 

 crossed head of wheat is now covered and allowed to 

 ripen. A careful operator can secure 50 per cent or 

 more of seeds in the flowers handled. The rough 

 treatment necessary injures many of the flowers so 

 that no seeds set. 



The seeds from a given hybridized spike may be 

 planted the second year in hills, one seed in a hill, a foot 

 apart each way. The seed from each of these spikes 

 may be sown in drills or broadcast for two or three 

 years until they have passed through their greatest 

 variation. Strong heads may now be selected and the 

 wheats from which to select good berries and the new 

 hybrids may be entered in the field crop nursery in hills 

 4x4 inches, in plots of from 2,000 to 100,000 plants 

 from each hybrid. The treatment of selection in the 

 nursery, of taking the best to the field tests and there 

 comparing them with the best standard wheats, may 

 be carried out in a manner similar to that described 

 in previous articles in regard to breeding wheat by 

 selection alone. The hybridizing is done simply to in- 

 crease the variation of an occasional plant toward a 

 more valuable type. The word "type" as used here 

 must not mean mere botanical appearance, neither must 

 it mean yield alone. The word "type" in its broadest 

 sense in breeding economic plants and animals means 

 that combination of qualities which give the largest 

 value, yield, disease resistance, hardiness, quality 

 and economy of production, together with other intrin- 



