CHAPTER II 



THE SOIL 



ACK to the soil," is the cry of many weary with the 

 harassing conditions of our present-day civilization. 

 The soil is the source from which nearly all our food-supplies, 

 directly or indirectly, are derived. To those who are engaged 

 in its cultivation, information as to its origin and nature should 

 be of special interest. 



Scientists tell us that there was not always soil. In the 

 early ages of our earth, when the molten materials had so far 

 cooled down that a solid crust of igneous rock was formed, 

 there was no soil spread over these rocks. When the tempera- 

 ture of the globe fell sufficiently low, the water-vapours began 

 to pour down and fill the hollows, and the action of water and 

 alternations of temperature dissolved and powdered portions of 

 the crystalline rocks, producing the soil and releasing valuable 

 mineral salts. In the course of ages the ever-active volcanic 

 forces distributed dust everywhere, and in this way helped to 

 form the soils, adding greatly to their fertility. 



The soil so formed, however, was not soil as we understand 

 the term. It was barren and dead. There were no bacteria 

 in it, and, consequently, only the lowest forms of plant life 

 could exist. The first forms of vegetation which appeared 

 in the steaming swamps were of a very low order algae, 

 lichens and mosses. From the decayed remains of these some 

 vegetable humus was formed in the course of time. They 

 were, in due course, succeeded by gigantic fern plants. It 

 was not till much later that flowering plants and trees appeared. 

 These could not appear until after the existence of bacteria to 

 furnish supplies of nitrogen to their root-systems. 



Darwin was much puzzled to account for the sudden appear- 

 ance of these high forms of vegetation amongst fossil remains. 

 On one occasion, writing to Dr Hooker, he described it as " an 



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