226 THE EARTH MADE READY FOR MAN 



no branches to sway, no chattering squu*rels to 

 gather the nuts that fell to the ground, no birds to 

 sing and fill the growing world with joy. Only the 

 hum of insects broke the absolute quiet of those 

 long, long stretches of marshy forest land. Big 

 dragon flies skimmed over the water of the black 

 pools, and locusts flew up from the ground with 

 their pecuUar buzzing sound. 



The rain still fell almost continuously and the 

 clouds hung low over the young world. The air, 

 too, was heavy over the thick, dark forests. It was 

 not like the clear, fresh air that we breathe with its 

 life-giving oxygen. Instead it was full of carbonic 

 acid gas, a gas which plants need for their growth 

 but which we cannot breathe and live. The long 

 scales of those early trees drank from the air that 

 gas which would have been a poison to the lungs of 

 animals or men. But to the trees it was life and 

 strength, and they grew so luxuriantly that no others 

 in all the world have been hke them. 



With their roots in the wet earth drinking in the 

 water, and their scales breathing in the heavy gas- 

 laden atmosphere, the trees of the mighty forests 

 grew and flourished. They flourished for so long a 

 time that you could not even measure it in your 

 thoughts. 



The long, slender scales dropped off from time to 

 time, and lay decaying in the water of the swamp. 

 The great, bristling branches dropped away as the 

 immense trees lifted their heads higher and higher 

 into the heavy atmosphere, moist with many showers. 

 The ripened spore cases scattered about their thick, 



