THE SOILS THAT LIVING THINGS HAVE MADE 19 



these pioneer plants lived forever. They grew old in 

 time : they died. But at their death they left a valuable 

 contribution to the world. They left the riches they had 

 accumulated : the elements they had secured from the 

 rocks, the substances of their growth, the wee beds of 

 soil they had secured from their forefathers, from the 

 donations of the wind, and from the gifts of air and 

 moisture. 



With this wealth available, there was no longer so 

 great a struggle. The decayed plant life in the crevices 

 and the deteriorated rock afforded better feeding grounds 

 for plants, more soil for support, more food for the needs 

 of maintenance and of growth. Consequently, this better- 

 ing of material necessities afforded increased opportuni- 

 ties for growth. A higher order of plants might now 

 come. So the small struggling plants, through a long 

 course of years, changed, now gradually, now suddenly, 

 into stronger varieties and species onward and upward 

 in the scale, until the time when soil was present in 

 abundance, when the higher plants, useful for food and 

 raiment, might be secure and safe, thoroughly fitted and 

 abundantly adapted to all the environmental conditions 

 needed for their complete development and growth. 



The work of plants in soil building. It follows, then, 

 that every kind of plant is a soil builder. The decay of 

 the plant at once produces a change in the texture of the 

 soil-making material. It is this addition of the organic 

 matter the dead plant that produces this constantly 

 performed miracle : for as the plant decays in the soil, the 

 particles of soil in contact with it likewise decay. In 

 other words, soil rotting is soil making. Decay of any 

 material in the soil organic or not favors and induces 

 the breaking down of the various complex compounds 

 forming the rock, or the raw or the untamed soils. 



