PLANT HTTTKITIOH. 23 



as it grows, as the feathers of a bird are removed during 

 the moulting season. No such cap exists at the end of a 

 branch or leaf. Again, while it is the office of a stem or 

 branch to produce leaves or scales, which are the repre- 

 sentatives of leaves, no root proper, as a rule, produces 

 leaves or flowers. 



Botanists make a distinction between "true roots" 

 which are the direct outgrowth from the original " rad- 

 icle " of the germinating seedling, and, in fact constitute 

 its direct continuation and " adventitious " roots, which 

 spring from the stem and branches, and which are only 

 indirectly derived from the primary root. For our pres- 

 ent purpose the distinction is unimportant. 



The root of a plant and its branches have different 

 forms and subserve different purposes. Whatever food is 

 taken up from the soil is taken up by them. They act 

 as stays and holdfasts, they serve as storehouses of nour- 

 ishment. Their form varies according to their use, their 

 needs, the competition with other roots, the conditions 

 under which they have to grow, and other circumstances, 

 not forgetting the heritage bequeathed to them by their 

 predecessors from generation to generation, for, like all 

 parts of the plant like the plant itself the root is the 

 product of what has gone before, adapted and modified 

 by the exigencies of the present. 



In this place we have to consider the roots chiefly in 

 their character as absorbent organs. The one function 

 common to all roots is absorption. They may have other 

 offices to fulfil, and they have very varied forms ; but 

 when we come to consider the main function of the root, 

 then we find simplicity and relative uniformity of struc- 

 ture. The thick, woody limb of an elm root, as we see 

 it exposed in a hedge-bank from which the soil has fallen, 

 is no organ of absorption ; the thick " bulbs " (so-called) 

 of a turnip or a beet, are not organs of absorption ; 

 neither are these latter, any more than the tubers of po- 



