II. 



PIONEER LABOURERS 



No one needs to be told that all living things require 

 food of one sort or another to keep them alive ; but 

 some people have fancied, even within the last hundred 

 years, that vegetables had such delicate appetites as to 

 need nothing but air and pure water for their susten- 

 ance. 



If this were so, then, of course, one sort of soil 

 would agree with them as well as another; and, in 

 fact, it would not be wanted at all except as a protec- 

 tion to their roots, and as a means of fixing them to 

 one spot and enabling them to stand against the wind. 



As a matter of fact, however, no vegetables live upon 

 a diet of mere air and water. 



But then, what of the seaweeds which float about in 

 the ocean ? Are there not vast meadows of weed far 

 away from soil or even rocks of any kind ? Does not 

 the ocean, moreover, swarm everywhere, from the 

 Polar regions to the Equator, with microscopic vege- 

 tables ? and is it not a fact that no seaweeds, not even 

 those which cling to the rocks, receive any of their 

 nourishment through their roots, and therefore must 

 live upon water ? 



