34 JSotans 



on a child's head is a hollow tube, we can guess 

 something of the fineness of the tubes which, banded 

 together form stems. 



Why should there be tubes? Why should you 

 have a throat to convey your food and drink to your 

 digestive organs ? The roots, by their mouths and 

 general surface, absorb moisture from the earth. This 

 moisture holds, in a dissolved state, many minerals 

 as salt, lime, soda, iron, chalk, silex, and others. The 

 moisture so gathered up, and laden, ascends through 

 the stem, passing up the tubes, and is distributed to 

 the leaves and general surface of the plant. 



By the leaves, or the green rind serving instead of 

 leaves, this material is turned into plant stuff. It is 

 then sent down through the tubes which distribute 

 the material to all 2:>arts of the plant, to build up 

 more cells and tissues. The long, thickened, united 

 cells make up the woody fibre of trees, the fine tis- 

 sues of the leaves. 



We can think of the stem as a vast series of tubes 

 placed side by side, perpendicularl}-, their walls 

 more or less thick, forming different substances in 

 the plant for different uses. These fibres are so firm 

 that they build up the timber known as iron wood, 

 and other kinds of hard wood, as solid and heavy 

 almost as iron. Thread, ropes, cloth, are spun and 

 woven from these vegetable fibres ; cloth is even 



