4 



SCIENCE OF GAEDENING. 



from removal or other causes, roots may sometimes be 

 curtailed or mutilated, the branches should in such cases 

 be shghtly pruned, to restore the balance between roots 

 and leaves. 



2.— Hoots. 



Situated at the base of a plant, these are the chief 

 means of supplying it with food, as well as maintaining it 

 in its position. They may be either fibrous or simple ; and 

 according to their capacity and disposition to form 

 numerous little branches, wdll the plant that possesses 

 them be either easy or difficult to transplant. Trees or 

 plants that have the habit of producing simple roots — 

 *' tap-roots," as they are usually called — are among the 

 most uncertain to remove, unless they are transplanted 

 young, when they wdll often be all the better for some 

 purposes if they have the tap-root shortened, and are thus 

 compelled to throw out side rootlets. The whole of the 

 cabbage tribe are of this description. Other kinds of 

 plants are thrown much sooner into fertility by one or 

 several removals, because the reduction of the roots 

 checks any propensity they may have to form superfluous 

 wood and foliage. This is the case with most fruit-trees, 

 and with many flow^ering plants. 



Roots spread themselves either horizontally or dow^n- 

 wards. Some plants have a natural leaning to either the 

 one or the other of these habits, and should be planted in 

 deeper or shallow^er soil accordingly. But in general, 

 those which have a great depth of earth to grow^ in wdll be 

 most luxuriant, while such as have their roots necessarily 

 kept near the surface of the ground will be more fruitful 

 and productive, as shall be hereafter explained. 



In very poor sandy or gravelly soils, and especially in 

 pure sand or gravel, the roots of plants have an interesting 

 tendency to multiply themselves, and produce a profusion 

 of fibres ; as if for the purpose of picking up nutriment 

 from a greater multitude of quarters, wdien it becomes 

 more scant}^ They likewise, in such positions, occa- 

 sionally form small tubers on the roots, apparently to 

 enable them to lay up moisture in themselves against the 

 occnrreuce of a particularly dry period, The former of 



