CHILDREN'S GARDENS 159 



bacteria are steadily decreased, and less and less humic 

 acids are formed, until finally the forces which turned 

 the rocks into soluble plant food, are no longer able 

 to work, and the almost pure, fine ground rock lies 

 barren or with a few stunted, wild plants, with no 

 visible line between top soil and subsoil. There is 

 no more dark top soil no covering plants, with 

 their leaves and roots to protect against wind and 

 flood, and the winds and waters that before meant 

 life and plenty, now bring desolation and barrenness. 

 If man stops such mismanagement, and merely 

 leaves the earth alone, Nature's forces will at once 

 set to work to bring back fertility. The winds and 

 the birds bring seeds, which will grow and die, and 

 the dead plants stay there. The earthworms cover 

 them, the oxygen works on them, the water soaks into 

 them and stays as long as it can. They turn dark 

 and break into pieces, the worms swallow them with 

 tiny pieces of rock and mix them thoroughly, and then 

 pass the mixture out again. Some bacteria find this 

 a good home and set to work. The next seed that 

 sprouts there finds more food ready than the first 

 did, and makes bigger growth before it dies, and so 

 adds more organic material for humus. If man keeps 

 away, animals come. In their lives they drop manure 

 on the land, and when they die, leave their bodies 

 all to be used for humus. So, season after season, 

 more plants and birds and animals come. But Nature 

 does not need to hurry only man hurries and wor- 

 ries and it may take one hundred or one thousand 



