CHAPTER IV 



MODERN INQUIRY INTO THE CROSS-FERTILIZATION 

 OF FRUIT, WITH PARTICULAR REFERENCE TO BEES 



FRUIT-GROWERS have hitherto had but vague ideas on 

 the subject of what is commonly spoken of as the fertil- 

 ization of fruit. Trees bloom, but do not always bear 

 crops. In the absence of frost and of an insect or fungus 

 to account for the failure the question arises as to whether 

 want of proper pollen is accountable. The effects of pollen 

 have to be considered : (i) on a variety fertilized with its 

 own pollen, (2) a sort crossed with the pollen of another 

 variety. 



To make the matter clear to a non-botanical reader 

 it should be stated that the flower of a fruit tree has both 

 male and female organs ; it can therefore be " self- 

 fertilized/' or in other words impregnated with its own 

 pollen. It may, however, be impregnated by pollen 

 brought by bees, by other insect agency or by the wind 

 from another variety of the same kind of tree. 



If a fruit tree is impregnated with its own pollen will 

 it crop freely, and will it bear as well as if impregnated 

 with pollen from another variety ? These are questions 

 which have engaged the attention of scientists during 

 recent years. 



The terms " self-fertile " and " self-sterile " are used 

 in connection with this matter. They suggest that a 

 variety bears fruit, or does not bear fruit, as the case 

 may be, when self-pollinated. But scientists sometimes 

 use the terms to distinguish, not the bearing, but the 



