342 TROPICAL NATURE 



It is true that brilliant tropical birds mostly belong to 

 groups which are wholly tropical as the chatterers, toucans, 

 trogons, and pittas ; but as there are perhaps an equal num- 

 ber of tropical groups which are wholly dull-coloured, while 

 others contain dull and bright-coloured species in nearly equal 

 proportions, the evidence is by no means strong that tropical 

 light and heat have anything to do with the matter. But 

 there are other groups in which the cold and temperate zones 

 produce finer -coloured species than the tropics. Thus the 

 arctic ducks and divers are handsomer than those of the 

 tropical zone ; while the king-duck of temperate America and 

 the mandarin-duck of North China are the most beautifully 

 coloured of the whole family. In the pheasant family we 

 have the gorgeous gold and silver pheasants in North China 

 and Mongolia, and the superb Impeyan pheasant in the tem- 

 perate North- Western Himalayas, as against the peacock and 

 fire -backed pheasants of tropical Asia. Then we have the 

 curious fact that most of the bright -coloured birds of the 

 tropics are denizens of the forests, where they are shaded 

 from the direct light of the sun, and that they abound near 

 the equator, where cloudy skies are very prevalent ; while, on 

 the other hand, places where light and heat are at a maxi- 

 mum have often dull -coloured birds. Such are the Sahara 

 and other deserts, where almost all the living things are 

 sand-coloured ; but the most curious case is that of the Gala- 

 pagos islands, situated under the equator, and not far from 

 South America, where the most gorgeous colours abound, but 

 which are yet characterised by prevailing dull and sombre 

 tints in birds, insects, and flowers, so that they reminded Mr. 

 Darwin of the cold and barren plains of Patagonia rather 

 than of any tropical country. Insects are wonderfully 

 brilliant in tropical countries generally, and any one looking 

 over a collection of South American or Malayan butterflies 

 would scout the idea of their being no more gaily -coloured 

 than the average of European species, and in this he would 

 be undoubtedly right. But on examination we should find 

 that all the more brilliantly-coloured groups were exclusively 

 tropical, and that where a genus has a wide range there is 

 little difference in coloration between the species of cold and 

 warm countries. Thus the European Vanessides, including 



