52 



PLANT BREEDING. 



remaiuiiig florets, as shown in fignre 18, this being done when the 

 flower is yet yonng and the antliers green or only slightly tinged with 

 yellow. The emasculated spike is covered by wrapping about it a 

 piece of tissue paper, tying above and below to prevent the accidental 

 introduction of foreign pollen. One or two days later, when the 

 flowers are fully developed, as shown by the opening of flowers of the 



4-40 

 A.M. 



5-08 

 A.M. 



4-43 

 A.M. 



4-45 

 A.M 



4-55 

 A.M. 



Fig. 16.— Opening of wheat flowers and anthers. 1 to ,';, opening of a wheat flower; r, to S, closing 

 of same; .9, closed flowers, with one anther hanging out; 10, wheat flower entirely closed; 

 11, the anther, with its attachment to the filament; 72 to 76, the progressive changes in the 

 opening of the pollen sacs; l.J, IG, anthers which have fallen out from the flower, thus inverting 

 their position and allowing the remaining pollen to fall out, the anther becoming shriveled and 

 brown. 



same age on neighboring spikes, pollen is brought froin the variety 

 chosen for the male parent and inserted, into the emasculated florets. 

 The cross-pollinated spike is again covered with the paper, to keep 

 out other pollen. The several resulting grains from each handled 

 spike are stored in a packet and so planted the second year that the 

 plant resulting from each seed has its individual plant number in the 

 nursery. The entire product of each plant is harvested, and full 



