HOW PLANTS BEGAN TO BE. 19 



nuts, or grains, are consumed by degrees and re- 

 duced once more to their original condition. 



Tlie animal eats what the plant laid by. He 

 also breathes — that is to say, takes oxygen into 

 his lungs. Within his body that oxygen once 

 more unites with the carbon and the hydrogen, 

 and is given out again in union with them as 

 carbonic acid and water. And the energy in tke 

 plant food, thus set free within his body, takes 

 the form of animal heat and animal motion — just 

 as the energy set free in the locomotive takes 

 -the form of heat and visible movement. Animals 

 are thus the absolute converse of plants; all that 

 the plants did, the animal undoes again. 



Briefly to recapitulate this rather dry subject, 

 — the plant is a mechanism for separating oxygen 

 from carbon and hydrogen, and for storing irp 

 sun-energy. The animal is a mechanism for 

 uniting oxygen with carbon and hydrogen, aad 

 for using the stored-up sun-energy as heat and 

 motion. 



And now you can see why it is so absurd to 

 ask. Which came first, the plant or the animal T*^ 

 You might as well ask. Which came first, the coal 

 or the fire ? All the living material in the world 

 was first made and laid up by plants. They alonfi 

 have the power to make living or energy-yielding 

 stuff out of dead and inert water or carbonic acid. 

 They are the origin and foundation of life. With- 

 out them there could be no living thing in tke 

 universe. It is in their green parts alone that 

 the wonderful transformation of dead matter into 

 living bodies takes place; they alone know ho-w 

 to store up and utilise the sunshine that falls 

 upon them. All the animal can do is to take the 



