The Nature of Plants 



In transplanting, great care should be taken to protect 

 the root hairs, for they shrivel and die almost at once if 

 exposed to the air. Their home is in moist soil, and 

 when taken out of the soil they are like fish out of water. 

 Even an exposure of a few minutes will kill them. Since 

 it is almost impossible to transplant a tree without 

 destroying a large portion of the root hairs, a correspond- 

 ing portion of the leafy growth should be removed. If 

 this is not done, the few remaining water gatherers can- 

 not keep the tree from wilting. (Exp. 4.) Trees are 

 usually transplanted when they bear no leaves, because 

 a tree will then need little water until it can develop 

 new root hairs. As most of the feeding root hairs are 

 at the ends of the roots, far out, 

 often, from the base of the tree, it is 

 there that we must apply water and 

 fertilizer. 



Through some power that is not 

 well understood, the roots select and 

 absorb in larger quantities those sub- 

 stances that the plant most needs as 

 food material ; and this same power 

 prevents them from absorbing other 

 substances in the soil water that are 

 not useful. Thus, although common 

 salt may be more abundant in some 

 particular soil water than potash is, 

 the amount of salt absorbed will be 

 small in comparison with the amount 

 of the much more needed potash that 



FIG. 6. Experiment to 



is taken in. show osmosis. 



The effect 

 of exposure 

 on root 

 hairs 



Why trans- 

 planted 

 trees are 

 trimmed 



Where to 



apply 



water 



The 



selection 

 of plant- 

 food 

 material 



