iv ON PLANT LIFE 123 



the Scotch Fir. When, on the contrary, the 

 pollen is carried by insects, the quantity nec- 

 essary is greatly reduced. Still it has been 

 calculated that a Peony flower produces be- 

 tween 3,000,000 and 4,000,000 pollen grains ; 

 in the Dandelion, which is more specialised, 

 the number is reduced to about 250,000 ; 

 while in such a flower as the Dead-nettle it is 

 still smaller. 



The honey attracts the insects ; while the 

 scent and colour help them to find the flowers, 

 the scent being especially useful at night, 

 which is perhaps the reason why evening 

 flowers are so sweet. 



It is to insects, then, that flowers owe 

 their beauty, scent, and sweetness. Just as 

 gardeners, by continual selection, have added 

 so much to the beauty of our gardens, so to 

 the unconscious action of insects is due the 

 beauty, scent, and sweetness of the flowers of 

 our woods and fields. 



Let us now apply these views to a few 

 common flowers. Take, for instance, the 

 White Dead-nettle. 



The corolla of this beautiful and familiar 



