HOW PLANTS BEGAN TO BE. 15 



the earliest animals could not possibly have been 

 lions and tigers; for lions and tigers could not 

 begin to exist till after there were deer and 

 antelopes for them to hunt and devour. Now 

 the general connection between animals and 

 plants is somewhat the same in this respect as 

 the general connection between beasts of prey 

 and the creatures they feed upon. For all 

 animals feed, directly or indirectly, upon 

 plants and their products. Even carnivorous 

 animals eat sheep and rabbits, let us say ; but 

 then, the sheep and the rabbits eat grass and 

 clover. In the last resort, plants are self- 

 supporting ; animals feed upon what the plants 

 have laid by for their own uses. Every animal 

 gets all its material (except water) directly or 

 indirectly from plants. In one word, plants are . 

 the only things that Jcnoiv how to manufacture j 

 living material. ? "*' y 



Eoughly speaking, plants are the producers 

 and animals the consumers. Plants are like 

 the pine-tree that makes the wood ; animals are 

 like the fire that burns it up and reduces it to 

 its previous unorganised condition. 



It is a little difficult really to understand the 

 true relation of plants and animals without 

 some small mental effort; yet the point is so 

 important, and will help us so much in our after 

 inquiries that I will venture upon asking you to 

 make that effort, here at the very outset. 



If you take a piece of wood or coal, you have 

 in it a quantity of hydrogen and carbon, almost 

 unmixed with oxygen, or at least combined with 

 far less oxygen than they are capable of uniting 



