192 MAKING BETTER PLANTS 



With good reason Luther Burbank is called " The Plant 

 Wizard of the West." 



137. The plant breeder produces new kinds of plants and 

 improves old ones, by crosses. He does not leave Nature 

 to produce crosses unaided. He experiments in new 

 crosses, such as Nature, left to herself, would perhaps 

 never secure. The genius of the breeder is shown mainly 

 in selecting the plants to cross. 



After the selection has been made for any one experi- 

 ment, the work itself is relatively simple. It is merely 

 a matter of cross-pollinizing the two plants and listing the 

 results. 



138. In cross-pollination the breeder is concerned mainly 

 with stamens and pistils. He must take the pollen from 

 one plant to fertilize the pistil of the other, and he must 

 see to it that that pistil is not fertilized in any other way^ 

 or he would not know what factors produced the result 

 which he finally obtains. 



First the plant whose pistil is to be fertilized is stripped 

 of most of its flower buds, so that the remaining ones may 

 develop vigorously. The remaining blossoms are de- 

 prived of their stamens, by the use of fine scissors. This 

 is done before the blossom fully opens, so as to make 

 sure that the anther shall not have already shed pollen 

 on the pistil. Great care is taken, of course, not to injure 

 the pistil when cutting away the stamens ; but the calyx 

 and corolla may be cut away also if they are in the 

 way. The remaining pistil is at once covered with a 

 small paper bag, tied on the flower stalk, so that neither 

 bees nor breezes may deposit undesired pollen there. 

 Insects, to be sure, are not likely to visit a mutilated 

 flower ; but it is necessary to be absolutely sure, or the 

 experiment is worth little. 



The breeder next takes pollen from the stamen of the 



