Chances of Life 299 



it depends entirely upon man's artificial aid. In time, 

 it is true, the difficulty might, and may, be overcome, 

 as it has been in the case of some other plants, either 

 by their becoming self-fertilizing, or by the insects of 

 their adopted country becoming accustomed to them; 

 but, in the meantime, without man it would die out. 



Of plants which require help, those are most likely 

 to prosper whose blossoms are least pecuHar in shape 

 and most easily got at. Tubular blossoms, such even 

 as the common clovers, require insects with trunks of 

 some length, because their nectar is so deeply hidden 

 that none but these can reach it. And insects do not 

 visit flowers where there is nothing to be gained. 



Composite flowers, such as the daisy, dandelion, 

 camomile, groundsel, and many others whose blossoms 

 grow together in flat heads, are easily fertilized by 

 almost any insects ; and what with this advantage and 

 the further one, that so many of the family have downy 

 seeds easily carried by the wind, composites are among 

 the most thriving and successful emigrants. 



