34 THE COLOURS OF FLOWERS, 



of the petal retains its original hue ; and this law is 

 strikingly illustrated in these two crowfoots. It is 

 remarkable, too, that in this respect they closely 

 resemble the half-faded flowers of the lesser celandine, 

 which become white from the edge inward as they 

 die. The petals also similarly vary, in number, 

 though to a less extent. White flowers of the sam-e 

 type as those of water-crowfoot are very common 

 among aquatic plants of like habit, and they seem to 

 be especially adapted to water-side insects. 



FIG. ga. Flower of water crowfoot (Rantmc-uhts aquatilis); white, with yellow 

 claws. 



In many Ranunculacecz there is a great tendency 

 for the sepals to become petaloid, and this peculiarity 

 is very marked in Caltha palus tris, the marsh-marigold, 

 which has no petals, but bright yellow sepals, so 

 that it looks at first sight exactly like a very large 

 buttercup. 



The clematis and anemone, which are more highly 

 developed, have white sepals (for the petals here also 

 are suppressed), even in our English species ; and 

 exotic kinds varying from pink to purple are culti- 

 vated in our flower-gardens. 



