The Daisy" s Pedigree. 25 



hone\', the insects largely gave up their habit of 

 plundering the pollen, and went from blossom to 

 blossom in search of the sweet nectar instead. As 

 they did so, they brushed the grains of pollen from 

 the stamens of one blossom against the pistil of the 

 next, and so enabled the flowers to set their seed 

 more economically than before. 



Simultaneously with this change from fertilisation 

 by the wind to fertilisation by insects, there came in 

 another improvement in the mechanism of flowers. 

 Probably the primitive blossom consisted only of 

 stamens and pistil, with, at best, a single little scale 

 or leaf as a protection to each. But some of the five- 

 rowed flowers now began to change the five stamens 

 of the outer row into petals ; that is to say, to produce 

 broad, bright-coloured, and papery flower-rays in the 

 place of these external stamens. The reason why 

 they did so was to attract the insects by their brilliant 

 hues ; or, to put it more correctly, those flowers which 

 happened to display brilliant hues as a matter of fact 

 attracted the insects best, and so got fertilised oftener 

 than their neighbours. This tendency on the part of 

 stamens to grow into petals is always very marked, 

 and by taking advantage of it gardeners are enabled 

 to produce what we call double flowers ; that is to 

 say, flowers in which all the stamens have been thus 



