IMPROVEMENT OF PLANTS 51 



a large-eared variety. Before the silk is seen on the 

 mother plant, he must tie a paper bag over the ear shoot. 

 Soon after the silks show, the plant-breeder carefully 

 pulls a tassel from a plant of the large-eared variety. 

 The pollen should be just ready to fly. He dusts this 

 over the silks of a selected plant and repeats this next 

 day, keeping the shoot under the bag until the silks dry. 



He may wish also to cause a big-boll variety of cotton 

 to grow a longer staple. Before the cotton-bud or young 

 bloom of the big-boll variety is ready to open, or about 

 sunset or sunrise, the plant-breeder opens or cuts away 

 the upper parts of the white petals, and with a knife, 

 small scissors, or fingers, removes every anther or pollen 

 case (Fig. 38). This is done before these cases have 

 opened and spilled their pollen on the pistil of the same 

 flower. A small paper bag is then tied over the injured 

 flower to keep insects from bringing any pollen to it. Pollen 

 from a selected long-staple plant can now be used, after 

 the pistil is more mature. After most of the cotton 

 blossoms have opened, or between eight and ten o'clock 

 in the morning, our plant-breeder comes back, removes 

 the paper bag, and gently rubs over the top of the pistil 

 a flower from a plant of the long-staple variety, on which 

 the pollen is beginning to shed. The particles of pollen 

 now cling to the sticky surface on the stigma and grow 

 there. The bag is replaced and removed five days later, 

 when, if all is well, a young boll is found. The seeds pro- 

 duced in that boll are the offspring of both varieties. 



If, however, the thirty to forty seeds from that boll all 

 grow into mature plants, the next year these' sister planta 



