THE WEALTH OF LIFE 



15 



Not a little of the colour of animals is due to the 

 physical nature of the surface, which is often iridescent ; 

 much, on the other hand, is due to the possession of pig- 

 ments, which may either be of the nature of reserve- 

 products, and then equivalent, let us say, to jewels, or 

 of the nature of waste-products, and thus a literal " beauty 



FIG. 3. HUMMING-BIRDS (Florisuga mellivord) VISITING FLOWERS. 



(From Belt.) 



for ashes." It is often supposed that plants excel 



animals in colour, but alike in the number and variety 



j 



of pigments the reverse is true. Then as to movement, 

 how much there is to admire : the bird's soaring, hover- 

 ing, gliding, and diving ; the monkey's gymnastics ; the 

 bat's arbitrary evolutions ; the grace of the fleet stag ; 

 the dolphin gambolling in the waves; the lithe lizards 

 which flash across the path and are gone, and the snake 

 flowing past like a rivulet ; the buoyant swimming of 



