78 ON THE ROOTS OF PLANTS. 



not necessary for my present purpose to discuss. 

 It ' is progressive in its growth, similar to the 

 branches, but in an inverted direction. 



As the branches of a tree are formed by a 

 very tender and succulent point, pushing up- 

 wards into the air, so the root penetrates down- 

 wards into the earth ; but as it has to make its 

 way through the pores, or between the particles 

 composing the soil it is planted in, which is 

 often close and tenacious, its first projecting 

 points are wisely adapted to the purpose, by 

 being much more minute and compliable, which 

 enables it to advance almost as readily as water. 

 After a root has effected a passage, it is en- 

 dowed with considerable expansive and repul- 

 sive powers, and thereby enabled to make its 

 way, by pushing off on all sides the encumbering 

 soil. When the soil is but partially submissive, 

 the root accommodates itself to the cavity, ad- 

 mitting its increase, however rugged and irre- 

 gular. Roots are, notwithstanding, impatient of 

 resistance, and at all times evince a partiality 

 for that soil which is most accommodating, and 

 run most evenly and luxuriantly, where they 

 meet with the least resistance, and the greatest 

 supply of nutriment. 



The office of the root is to collect and supply 

 i the food, which forms and determines the future 



8* 



