Cleavers. 123 



fertilisation upon many different species of winged 

 visitors are white. And, indeed, the sort of colour in 

 each kind of stellate flower (as in all others) depends 

 largely ui)on the sort of insects it wishes to attract. 

 Thus the little field-madder, which has a long tube 

 and is fertilised by honey-suckers of a high type, is 

 blue or pink, as all the family once was, no doubt, 

 before it began to bid for more vulgar aid. Then the 

 lesser woodruff, or squinancy-wort, whose tube is 

 shorter, has white cups tinged with lilac. The goose- 

 grass and most of its neighbours, whose flowers have 

 undergone still greater degeneration, are simply white, 

 because they wish to please all parties equally, and 

 white is of course the most neutral colour they could 

 possibly assume. Finally, the lady's bedstraw, which 

 has no tube, depends upon little colour-loving beetles 

 for fertilisation, and, like many other beetle flowers, it 

 is bright yellow. 



This order of degradation exactly reverses the 

 upward order of chromatic progress ; for, as flowers 

 advance in type, they pass from yellow, which is the 

 lowest colour, through white, pink, red, and lilac, to 

 purple and blue, which are the highest. And when 

 through any special cause they begin to retrogress, 

 they pass backw ard through the same stages in inverse 

 order. 



