HOW PLANTS BEGAN TO BE. 21 



present day every living being, whether plant or 

 animal, is the product of a previous living being, 

 its parent, or of two previous living beings, its 

 father and mother. 



Why should this be so? Well, if you think 

 for a moment, you will see that it results almost 

 naturally from the other facts we have so far 

 considered. For the plant is a machine for mak- 

 ing living matter out of water and carbonic acid, 

 under the influence of sunlight. As long as sun- 

 light, direct or reflected, in sun or shade, falls 

 upon -a green plant, the plant goes on taking up 

 carbonic acid from the air by means of its leaves, 

 and water from the earth by means of its roots, 

 and continues to manufacture from them fresh 

 living material. Thus it must be always growifig, 

 as we say ; in other words, the mass of living 

 material must be constantly increasing. Now, it 

 results from this that the plant would grow in 

 time unwieldily large; and in simple types, when 

 it grows very large, it splits or divides into two 

 portions. That is the real origin of what we call 

 REPRODUCTION. In its simplest forms, reproduc- 

 tion means no more than this — that a rather 

 large body, which cannot easily hold together, 

 divides in two, and that each part of it then con- 

 tinues to live and grow exactly as the whole did. 



This seems odd and unfamiliar to you, because 

 you are thinking of large and very advanced 

 plants, like a sweet-pea or a potato. But you 

 must remember that we are dealing here with 

 very early and simple plants, and that these early 

 and simple plants consist for the most part of 

 tiny green mites, floating free in water. They 

 are generally invisible to the naked eye, and are 

 in point of fact mere specks of green jelly. Yet 



