TESTING THE RESULT 



193 



other plant selected, and applies it to the prepared pistil 

 with his finger or with a brush. Usually he first moistens 

 the stigma slightly, to make the pollen adhere to it better. 

 139. Testing the Result. After all this work, the pollen 

 may not fertilize the ovules, and no seed may be formed. 

 That is, these two plants may refuse to breed together. 

 In a vast number of experiments this is the case. 



VARIATION IN PLANT BREEDING. 

 Note the differences in size and shape among these kernels of corn. 



If the ovules are fertilized, seed is formed, and this 

 seed will produce a plant different from its parents. But 

 until this new plant matures, it is impossible to tell 

 whether the plant is an improvement or not. From thou- 

 sands of crosses the breeder selects only a few to preserve. 



In some cases it takes years before the breeder can tell 

 whether his new cross is worth preserving. If he has 

 been working with apples, he must wait until the new 

 plant produces fruit; and then if the result is disappoint- 

 ing, he must begin over again. It is fortunate, therefore, 

 that he can hasten results with such plants by grafting. 

 If a sprout for the new apple tree, when a year old, is 



