The Origin of Wheat. 153 



petals, which would induce insects uselessly to 

 plunder their precious stores : and so all those rushes 

 which showed any tendency in that direction would 

 soon be weeded out by natural selection ; while those 

 which produced only dry and inconspicuous petals 

 would become the parents of future generations, and 

 would hand on their own peculiarities to their de- 

 scendants after them. Thus the existing rushes are 

 all plain little lilies with dry brownish flowers, speci- 

 ally adapted to wind-fertilisation alone. 



Among the rushes themselves, again, there are 

 various levels of retrogressive development — retro- 

 gressive, that is to say, if we regard the lily family 

 as an absolute standard ; for the various alterations 

 undergone by the different flowers are themselves 

 adaptive to their new condition, though that condition 

 is itself decidedly lower than the one from which they 

 started. The common rush and its immediate con- 

 geners resemble the lilies from which they spring in 

 having several seeds in each of the three cells which 

 compose their pistil. But there is an interesting 

 group of small grass-like plants, known as wood- 

 rushes, which combine all the technical characteristics 

 of the true rushes with a general character extremely 

 like that of the grasses. They have long, thin, grass- 

 like blades in the place of leaves ; and what is still 

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