66 THE BEGINNER'S GARDEN BOOK 



Why have we been watering the plants that we have studied, 

 by keeping the sand in the testers, or the blotting paper, 

 moist ? It is, of course, because we believe that the plant 

 needs the water. Now it is interesting to try to prove this. 



Take one of the pots which we have previously used 

 for sprouting seeds, choosing one which has one or two strong 

 plants. 1 Take another which has no plants, but has about 

 the same amount of soil. Cover them with cardboard in 

 such a manner as to prevent evaporation. The cardboard 

 for the pot containing the plants will have to be slit 

 for each plant, and the slits sealed again with wax. Keep 

 both pots in the light, so that the plants will thrive. 

 Each pot should be set in a tin can. An inch above the bot- 

 tom of each pot make a dent on the can, and fill the can with 

 water up to the dent. Every day refill the cans to the same 

 marks, keeping a record of the amount of water poured into 

 each can. A few days will show a difference in the amounts of 

 water used : the plant uses much ; the other pot, after the 

 first day (when the earth naturally took up a good deal of 

 water), almost none at all. 



We can make either of these experiments very sure, if we 

 wish, by keeping the water from the pots or tumblers for a 

 couple of days. The plants will wilt. But if water is 

 given again, they will recover. 



A plant, then, keeps itself alive by taking water from 

 the earth around its roots. How does it take up the water, 

 and where does the water go ? 



To answer the first question we need first to examine 

 again the roots of a plant, preferably a radish. The roots of 

 even the very youngest radish are bristling with tiny hairs, 

 easily seen without a glass. With other plants we may have 



1 At the time this experiment is begun, a few radish seeds should be started 

 in another tumbler, or pot. 



