DOG'S MERCURY AND PLANTAIN, 141 



with a groundsel of some remote future 

 century, I have little doubt we should find 

 its bell-shaped petals as completely degraded 

 as those of the plantain in our own day. 



The general principle which these cases 

 illustrate is that when flowers have always 

 been fertilised by the wind, they never have 

 brilliant corollas ; when they acquire the 

 habit of impregnating their kind by the 

 intervention of insects, they almost always 

 acquire at the same time alluring colours, 

 perfumes, and honey ; and when they have 

 once been so impregnated, and then revert 

 once more to wind-fertilisation, or become 

 self-fertilisers, they generally retain some 

 symptoms of their earlier habits, in the 

 presence of dwarfed and useless petals, some- 

 rimes green, or if not green at least devoid of 

 their former attractive colouring. Thus every 

 plant bears upon its very face the history of 

 its whole previous development. 



