Root Work 



substances used by the plant in building up its 

 body, and it fixes the plant in the soil. 



The younger parts of the root have thin, delicate 

 walls through which (although no visible holes are 

 present in them) water and substances dissolved in 

 it may easily pass. The extent of surface of these 

 parts of the roots is increased by the outgrowth of 

 many cells so as to form delicate projections. These 

 outgrowths are called root-hairs, and though their 

 life is short, they are continually replaced by new 

 ones as the root lengthens and branches, and they 

 always occur within a short distance of the tips of the 

 roots. All the water, etc., absorbed by the plant 

 must find its way through the surface of the root- 

 hairs or of the delicate roots which produce them. 

 The useful water in the soil forms a film over the 

 surface of the particles of which the soil is composed, 

 and from these particles certain substances are 

 dissolved. In order to obtain the water the root 

 and root-hairs must be in close contact with the 

 soil particles. 



Chemical analysis of plants has sho-wn that the 

 following elements are universally present in them, 

 viz. carbon, hydrogen, oxygen, nitrogen, sidphur, 

 phosphorus, calcium, magnesium, potassium, iron, 

 chlorine, silicon, and sodium. Experiments have 

 shown conclusively that the first ten in this list are 

 essential, the others needless or merely accessory. 

 Except carbon, all are obtained from the soil in 



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