MANUAL OF NATURE) STUDY. 
95 
take to our tomes ? What is necessary to be done 
before tbe sheep’s back will furnish our clothing, or 
the tree onr furniture ? Then what must be done 
before the elements of the ground will nourish onr 
bodies? As the manufacturer and tailor change 
the wool into clothing, and the cabinet maker the 
trees into furniture, so do plants imbibe the elem¬ 
ents of soil and other foods for animals to eat. 
How do plants accomplish such a wonderful task ? 
1. By keeping the original rocks moist, and by 
decay of leaves, mosses, etc., producing carbonic 
acid which dissolves the rocks, and thus gives more 
soil for a more luxurious growth of vegetation. 
2. By breaking rocks in pieces by the penetrat¬ 
ing power of roots. 
3. By holding moisture back along the sides of 
hills to prevent its running away in floods, until 
the plant life can have time to utilize the food dis¬ 
solved in it. 
As to manner of food storage, plant substance 
and seed factories, see topics already written 
in previous pages of this book. What have 
animals done to repay the plant kingdom for 
all this labor ? Take the fish-worm for example. 
The fish-worm, or earth-worm, has so burrowed or 
channelled the ground that it is difficult to find a 
place where they have not been. 
