22 THE STOKY OF THE PLANTS. 



own days at least spontaneous generation does 



not take place perhaps because all the available 



material is otherwise employed, perhaps because 



the conditions are no longer favourable. At any 



/rate, we have every reason to suppose that at the 



' 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. \ 

 making living ma^tey m\t pf water anH carbonic 

 acI37~under the influence of sunlight. As long 

 as sunlight, 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 |resh living material. Thus it must be 

 always groiving, 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 KEPKODUCTION. In 

 its simplest forms, reproduction 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 continues to live and grow 

 exactly as the whole did. 



This seems odd and unfamiliar to you, because 



