PRACTICAL POLLINATION 255 



It may well be doubted whether the existing 

 races of cultivated wheat could perpetuate their 

 kind, if put upon their own resources in com- 

 petition with wild plants, for a dozen or two 

 dozen years. 



The habit of self-fertilization may preserve for 

 a certain number of generations a plant that 

 would otherwise have been completely extermi- 

 nated; but at best it marks a stage of degenera- 

 tion and decline. The plant that follows it is in 

 a sense retracing its steps down the ladder of 

 evolution by which its ancestors have made ascent. 



And so it is not surprising to find that the vast 

 majority of the useful plants of orchard and 

 garden have kept up the traditional alliance with 

 the insects to which they owe the multiplicity of 

 their specific forms and the virility and adapt- 

 ability of the individual members of their 

 organization. 



THE WISEST OF PLANTS 

 It is flowers of the great brotherhood of insect 

 lovers, then, that chiefly claim the attention of 

 the plant experimenter, because these are the 

 ones that make up the chief census of orchard 

 and garden. 



As a matter of course it is plants of this 

 fraternity that are of interest to the amateur, 



