THE EVOLUTION OF THE FLOWERS 77 



the genial climate of the whole earth lasted long 

 enough to permit a great expansion of the flowering 

 plants. The landscape slowly took on the features 

 which make it familiar to us to-day. But the world 

 was to pass through a mightier chill than ever before 

 its modern appearance would be finally reached. 



At the time of the spread of the flowering plants 

 there was also a rapid evolution of the insect world. 

 Now the bees and wasps, ants and flies and butterflies, 

 came upon the scene. We saw that the coal forests 

 had had only primitive large flying insects, beetles, 

 and other lowly types. We saw that wings are 

 developed frequently in the course of evolution. 

 Wherever there is a great struggle for life, some of 

 the hunted will try to escape into the broad free at- 

 mosphere which floats above the teeming ground. 

 Even fishes, in the tropics, have developed a certain 

 power of flying, or rather "planing," away from their 

 enemies; and to see a flock of these ''flying fishes" 

 rise out of the water — if they are near the ship, you 

 can sometimes see the dark shade of a shark approach- 

 ing — gives one an idea of the beginning of the evolu- 

 tion of flight. You might almost say that the same 

 thing is happening under our eyes in England to-day. 

 Man is struggling to rise out of his congested roads 

 and travel in the free air. So insects, and reptiles 

 and birds, bats and ''flying foxes," have at different 

 times escaped from the struggle on the ground by 

 developing wings. 



