THE FLOWERING PLANT. 



49 



it. The fluid passes through the little mouths of the 

 sponges into small tubes, or ducts, which carry it up the 

 root and stem to the leaves. If you cut a very, very 

 thin slice lengthwise of the stem, and put it under the 

 microscope, you will see these vessels plainly, because 



Fig. 38. 



Stalk of Leaf, cr Petiole. 



Bundle of Tubes passing 

 out of Stem to make 

 the Little Foot-stalk, or 

 Petiole. 



Stem. 



Aik Tubes, showing the 

 Coiled Springs. 



their walls are all dotted (Fig. 37). There are other 

 tubes in the stem, very curiously made, for carrying air. 

 They seem to be filled with little coiled springs, which 

 keep the sides from coming together, just as you may 

 have noticed India-rubber gas-tubing, which has coiled 

 wire inside to keep the tube open (Fig. 38). Some of 



3 



