108 



OUR FORESTS 



corsairs came in by sea and grasped the slackly defended riches, and the 

 little winged poisoners of the night struck again and again, until grass 

 grew in the streets, and the wharves crumbled where they stood. "Finally, 

 the wretched remnant of a great people wandered away into the more 

 wholesome hills, the marshes rotted in the heat and grew up in coarse 

 reeds where corn and vine had flourished, and the city melted back into 

 the wasted earth." l 



Prevention of Erosion by Covering of Organic Soil. - We have 

 shown how ungoverned streams might dig out soil and carry it 



- 



. 



Result of deforestation in China,. This laud has been ruined by erosion. 

 (Carnegie Institution Research in China.) 



far from its original source. Examples of what streams have done 

 may be seen in the deltas formed at the mouths of great rivers. 

 The forest prevents this by holding the water supply and letting it 

 out gradually. This it does by covering the inorganic soil with 

 humus or decayed organic material. In this way the forest floor 



1 Elizabeth Bisland and Anne Hoyt, Seekers in Sicily. John Lane Company. 



