EXERCISE 18 



RELATION OF ROOT HAIRS TO SOIL 

 Materials. Seedling plants growing in sand, loose soil, or sawdust. 



Directions for work. To determine whether the root hairs 

 have any close relation to the soil, gently remove a plant which 

 is growing in very loose soil or in sand or sawdust. After 

 noting how much soil adheres, gently shake the plant and note 

 results. Then wash the roots by moving them to and fro in a 

 vessel of water. Finally, mount one of the washed roots for 

 examination with the hand lens or microscope. 



Do you find that washing removes all the soil? What is 

 your opinion regarding the original position of the root hairs 

 with relation to the soil particles? Do the root hairs appear 

 to be so placed as to favor absorption of the water which 

 moistens the surfaces of the soil particles? 



References 



BERGEN and CALDWELL. Practical Botany, pp. 6-9. 

 BERGEN and CALDWELL. Introduction to Botany, pp. 9, 10. 



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