178 THE EARTH MADE READY FOR MAN 



After a time soil collects in these fissures, some of 

 it being blown in by the wind. This makes a home 

 for the seeds and spores, which grow into graceful 

 rock-ferns and beautiful nodding columbines. Many 

 times trees start to grow in these fissures, and their 

 roots grow and spread until they spht the rocks apart. 

 In time one part of the rock may even break entirely 

 away from the other. It takes a long, long time for 

 this to happen, for the growing roots work very slowly. 



Frost, besides splitting rocks, does other work 

 which the boys and the squirrels appreciate. It 

 ripens the nuts and splits open their outer shells. 

 You would have a sorry time getting chestnuts if you 

 had to crack open aU the burrs yourselves. And how 

 would the poor squirrels fare, do you suppose? Now, 

 in the same way the frost opens up the earth and 

 loosens it. 



Have you ever seen on cold mornings in the early 

 spring long crystals of ice which extend down into 

 the ground? You break them under your feet as 

 you walk along. These long hard crystals are like 

 little plows, loosening and turning over the closely 

 packed soil at the surface of the earth. They do in 

 the cold weather a little of the same work on the soil 

 that the earthworms do in summer. One often sees 

 these crystals of ice in a woodland path, where they 

 make little caves just under the surface of the earth. 

 They look Hke pillars in a fairy temple. When you 

 see them you will step aside so as not to crush such 

 beautiful frost-work. 



On a bright summer morning you may see the grass 

 and bushes sparkling with dew. But in the cold 



