The ^Discoveries of Four Great botanists 



numbers, continually crowding" out all their less 

 vigorous self-fertilized competitors of the same 

 species, at length to become entire masters of the 

 field and the only representatives left to perpetuate 

 the line of descent. 



Everything in nature is in a state of change or 

 evolution, and we can find flowers of all degrees in 

 the scale of cross-fertilization, from those at a low 

 stage of development, adapted to insects as a whole, 

 but not to any special class, and often retaining, as 

 a last resort, the power of self-fertilization, to those 

 which, like the orchid, can be fertilized only by a 

 single species of insect, and actually perish if it fails 

 to visit them. 



The question here arises, are there any flowers 

 that are invariably self-fertilized ? There are a 

 few. 



CLEISTOGAMOUS BUDS 



A good example of such a flow^er is found in the 

 violet, which produces two distinct blossoms on the 

 same plant, one a little blind or '' cleistogamous " 

 flower, which <^rows close to the fri'ound and which 

 is always self-fertilized, and the other the show}^ 

 blossom, with which we are all familiar, this latter 

 blossom being formed for cross-fertilization. 



The blind flower is rarely seen, as it is a tiny 



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