r INTRODUCTION 29 



Obi the most beautiful spectacle, he says, 

 which he had ever witnessed. Behind him 

 were barren rocks and the snows of winter, in 

 front a great plain, not indeed entirely green, 

 or green only in places, and for the rest 

 covered by three flowers, the purple Siberian 

 Iris, the golden Hemerocallis, and the silvery 

 Narcissus green, purple, gold, and white, 

 as far as the eye could reach. 



Wallace tells us that he himself has de- 

 rived the keenest enjoyment from his sense 

 of colour : 



" The heavenly blue of the firmament, the 

 glowing tints of sunset, the exquisite purity 

 of the snowy mountains, and the endless 

 shades of green presented by the verdure-clad 

 surface of the earth, are a never -failing 

 source of pleasure to all who enjoy the ines- 

 timable gift of sight. Yet these constitute, 

 as it were, but the frame and background of 

 a marvellous and ever-changing picture. In 

 contrast with these broad and soothing tints, 

 we have presented to us in the vegetable and 

 animal worlds an infinite variety of objects 

 adorned with the most beautiful and most 



