CHAPTER II. 



GENERAL LAW OF PROGRESSIVE COLOURATION. 



If the earliest petals were derived from flattened 

 stamens, it would naturally follow that they would be 

 for the most part yellow in colour, like the stamens 

 from which they took their origin. How, then, did 

 some of them afterwards come to be white, orange, 

 red, purple, lilac, or blue ? A few years ago, when the 

 problem of the connection between flowers and insects 

 still remained much in the state where Sprengel left 

 it at the end of the last century, it would have seemed 

 quite impossible to answer this question. But now- 

 adays, after the full researches of Darwin, Wallace, 

 Lubbock, and Hermann M tiller into the subject, we 

 can give a very satisfactory solution indeed. We now 

 know, not only that the colours of flowers as a whole 

 are intended to attract insects in general, but that 

 certain colours are definitely intended to attract 

 certain special kinds of insects. Thus, to take a few 

 examples only out of hundreds that might be c"ted, 

 the flowers which lay themselves out for fertilisation 

 by miscellaneous small flies are almost always white ; 

 those which depend upon the beetles are frequently 

 yellow ; while those which specially bid for the favour 



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