20 FRUIT GROWING FOR AMATEURS 



of male and female flowers, which would be quite easy to under- 

 stand. It is more difficult of explanation. Why is a self- 

 sterile blossom so incapable ? Its ovaries become fertile when 

 strange pollen is introduced : its pollen can fertilise strange 

 ovaries. 



It is not Nature which is at fault ; rather it is man's inter- 

 ference with Nature, either when he deliberately produces cross- 

 bred varieties or when he perpetuates freaks which Nature 

 would soon have squeezed out of existence. Man having intro- 

 duced a new variety, e.g. Cox's Orange Pippin, perpetuates 

 it by grafting or budding. Nature perpetuates from seed, 

 but Cox's Orange Pippin grown always from seed very soon 

 reverts to something very different, and in course of time pro- 

 bably retrogrades to Pyrua Malus or some other wild Apple 

 which will assuredly be as self-fertile as the popular cross-bred 

 Cox is self-sterile. 



Nature has various agents for pollenising fruit flowers, but 

 of these bees are far the most important, because unlike other 

 insects they carry the pollen from flower to flower and tree to 

 tree, whereas the various flies, wasps, etc., are unable to do so 

 to any appreciable extent. These latter may indeed help in 

 pollenising self-fertile blooms by shaking off the pollen, just 

 as a camel-hair paint brush might do. Wind has no great 

 pollen distributing and carrying power. 



It should be noted that if a self-sterile flower A is fertilised 

 by the pollen of a self-sterile flower B, it does not follow that 

 B can be fertilised from A the affinity need not be mutual, 

 though it often is, and it is obviously' desirable that it should 

 be so. 



From what has been written above it may appear that there 

 are many obstacles in the way ; but in practice this is not so. 

 The writer's garden contains seven varieties of Plums, twenty- 

 five of Apples, and fourteen of Pears, all of which bear fruit 

 freely except one, viz. Catillac Pear, which seldom bears any- 

 thing, and will continue to be an unprofitable tree until an 

 affinity is found and provided. Since neighbouring gardens 

 in no way help, it follows that the necessary affinities must 

 be present, though in some cases unknown as such to the owner. 

 Many of his varieties are self-sterile. 



It may be added that many affinities have yet to be discovered 

 and many varieties have stilj to be classified as fertile or sterile. 



