XI THE SPECIAL COLOURS OF PLANTS 333 



flowering creation subser^dent to his daily wants. His butter- 

 cup, his dandelion, and his meadow-sweet grow thick in every 

 English field. His thyme clothes the hillside ; his heather 

 purples the bleak gray moorland. High up among the alpine 

 heights his gentian spreads its lakes of blue ; amid the snows 

 of the Himalayas his rhododendrons gleam with crimson light. 

 Even the wayside pond yields him the white crowfoot and the 

 arrowhead, Avhile the broad expanses of Brazilian streams are 

 beautified by his gorgeous Avater-lilies. The insect has thus 

 turned the whole surface of the earth into a boundless flower- 

 garden, which supplies him from year to year with pollen or 

 honey, and itself in turn gains perpetuation by the baits that 

 it oflers for his allurement." ^ 



Concluding Bemarh on Colour in Nature. 



In the last four chapters I have endeavoured to give a 

 general and systematic, though necessarily condensed view of 

 the part which is played by colour in the organic world. We 

 have seen in what infinitely varied ways the need of conceal- 

 ment has led to the modification of animal colours, Avhether 

 among polar snows or sandy deserts, in tropical forests or in 

 the abysses of the ocean. We next find these general adapta- 

 tions giving way to more specialised types of coloration, 

 by which each species has become more and more harmonised 

 with its immediate surroundings, till we reach the most 

 curiously minute resemblances to natural objects in the leaf 

 and stick insects, and those Avhich are so like flowers or moss 

 or birds' droppings that they deceive the acutest eye. We 

 have learnt, further, that these varied forms of protective 

 colouring are far more numerous than has been usually sus- 

 pected, because, what appear to be very conspicuous colours 

 or markings when the species is observed in a museum or in 

 a menagerie, are often highly protective when the creature is 

 seen under the natural conditions of its existence. From 

 these varied classes of facts it seems not improbable that 

 fully one-half of the species in the animal kingdom possess 

 colours which have been more or less adapted to secure for 

 them concealment or protection. 



Passing onward we find the explanation of a distinct type 

 ^ The Colour Sense, by Grant Allen, p. 95. 



