120 THE WORK OF PLANTS 
and helps to make new living matter to replace that 
which has been used up in growth or work. 
The case with the plants 1s somewhat similar, though 
their structure, of course, is very different. The starch 
made in the green leaf is the solid food, though it is 
not taken in by the plant in that form. It must be 
digested and changed to a form of sugar by the action 
of a Juice (a ferment) in the life substance. Here it 
meets other food substances absorbed by the roots. 
Then by a process of assimilation similar to that which 
takes place in our own bodies, new living material is 
made. 
So while plants and animals get their food by differ- 
ent methods, and in different forms, it is finally made 
into living material in the same way. The life sub- 
stance of plants is the same as the life substance of 
animals. 
