THE ROOT -HAIRS 



9 



them are horizontal and lie near the top of the ground. 



Some roots, as of willows, go far hi search of water. They 



often run into wells and drains, and into 



the margins of creeks and ponds. Grow ^, 



plants in a long narrow box, in one end of 



which the soil is kept very dry and in the 



other moist: observe where the roots grow. _ 



28. The feeding surface of the roots is 

 near their ends. As the roots become 

 old and hard, they serve only as channels 

 through ivhich food passes and as hold -fasts 

 or supports for the plant. The root -hold 

 of a plant is very strong. Slowly pull - 

 upwards on some plant, and note how 

 firmly it is anchored in the soil. With the 

 increase in diameter, the upper roots often 

 protrude above the ground and become 

 Iracwg buttresses. These buttresses are 

 usually largest in trees which always have 

 been exposed to strong winds. Fig. 10. 



29. THE ROOT-HAIRS.— The larger part 

 of the nourishment gathered by the root 

 is taken in through root-hairs. Fig. 11. 

 These are very delicate x>rolonged surface 

 cells of the roots. They are borne for a 

 short distance just back of the tip of the 

 root. 



30. The root -hairs are very small, often 

 invisible. They, and the young roots, are 

 usually broken off when the plant is 

 pulled up. They are best seen when 

 seeds are germinated between layers of l^ji 

 dark blotting paper or flannel. On the i 

 young roots, they will be seen as a mould- ^-- '^''"*'^ ^°°^^ °^ 



•,., -., . .^ trumpet creeper 



like or gossamer - like covering. Root- or tecoma. 



, „.«,^_— vsv 



f^^"^* 



