i THE PLANT AND WATER 9 



That water- vapour is escaping from the leaves 

 can further be shown by a very simple experiment. 



Experiment 7 

 Pick a fresh green leaf, and lay it lightly lack 



PIG. 4. Section of leaf showing stomata. 



downwards on a polished piece of metal (the lid of a 

 tin can). After a few seconds pick it up again. 

 The metal surface under the leaf is covered with 

 little drops of water, owing to the escaping vapour 

 condensing on the cold surface. 



Now turn the leaf over, and place the front or 



