ON THE KOOTS OF TREES. " 337 



first root. The tap root is the third division— it is of the ut- Third division, 

 most consequence to attend to the shoots that belong to the o*" ^^F'"°^- 

 different roots — it is the tap root which always forms the 

 leading shoot of the tree ; and if it is cut, it will, without 

 doubt, spoil that part, by forming two middle stems to the tree ; 

 at least I have generally found this to be the case j and as the 

 beauty of a tree depends much on the perpendicular height of 

 its single pillar, the custom they have in most nurseries of cur- 

 tailing the tap root, is a most vicious one. A row of alburnum 

 is seldom found in this part of the rooc ; for it increases this 

 way but once in seven or eight years — its growth is, indeed, 

 in a different manner, shooting from the end ; for if I sever the 

 smallest piece from the tap-root, it will very soon throw out 

 two ends, and if these are cut, two more will be added to each, 

 and it then ceases to shoot perpendicularly j losing its form, 

 and then growing like a common root, whereas a tap-root dra^fis 

 out at the end like a telescope, one inch each shoot ; and if it 

 is dissected with care, two or three of these divisions will be 

 found. What is the use of the tap-root ? ■ By shooting per- Useof thetap- 

 •pendicularly down, to fix the tree firmly in the ground, and '"°'^^" 

 keep it straight in that position ; then it is surrounded by ra- 

 dicles which perpetually pump up from every different soil, as 

 it proceeds in depth, what other roots cannot attain, matter 

 which, mixed with what the higher grounds bestow, serves to 

 bring a variety to compound the different ingredients required 

 for ihe various nourishment of the tree, probably minerals are 

 wanted to form the juices of the hark j and I doubt not that 

 the deep descent of the tap-root is most necessary to the health 

 and vigour of the tree. How improper, then, is the custom Never to cwt 

 of cutting it, and curtailing also many of the other roots, each t^® roots, 

 of which has its appropriate branch, which will, of course, 

 suffer in decay for the delapidations produced by the ignorance 

 of the gardener. But the loss of the tap-root can never be 

 remedied. It can no longer serve as a deep well, to gain not 

 only a quantity <'f moisture from the number of rills it may 

 meet with in its descent, bat also matter from a variety of soil, 

 and innumerable productions it passes in its way. The tap-root 

 is, then, like the radicles, only a larger pump to collect andE 

 throw up all that it can select of water and other juices. The 

 second part of the root is the reservoir for collecting the mate- 

 SvPPLEMENT,— Vol. XXXIV. No. 156. Z^ rials; 



