128 



duration^ a fact which has not hitherto been observed by 



Pl)ytologists. 



As to the taproot, it appears, that a good deal of exaggera- 

 tion has prevailed among late writers, respecting its import- 

 ance to trees, which has been affirmed to be quite paramount. 

 Hence the doctrine, that if it be cut off by transplantation, or 

 other means, the tree has no longer the power either of re- 

 newing or reproducing it, or even of growing to timber of 

 any magnitude. This opinion, however, is founded in error, 

 and cannot be supported by experience. From the develop- 

 ment of woody plants, we are warranted in believing, that, 

 in infancy, the taproot is indispensable to their vigorous 

 growth. But the fact, that in trees of mature age, when cut 

 down, the taproot is no longer distinguishable from the other 

 roots, sufficiently shows that the importance which it once 

 possessed, does not continue to a late period of their age. 



From my own experience, I am enabled to adduce a direct 

 confirmation of the analogy above mentioned. In sundry 

 instances, when I have had occasion for the second time to re- 

 move a tree, the power of renovation appeared conspicuous, 

 in the fresh set of taproots that was generated. In the 

 same way, respecting the top, on heading down a spiral tree, 

 in order to communicate to it the spreading character, it was 

 found, that numerous growths were sent out, instead of the 

 leading-shoot, which had been displaced by the pruning- 

 knife; and when it came to be shortened a second time, 

 there appeared, of course, a still greater multiplicity. The 

 truth seems to be, that no physiological observations as yet 

 made are inconsistent with this doctrine. Art or accident 

 may cut off or shorten either the taproot, or the preeminent 

 shoots of the top, but the plastic powers of most trees will 

 soon renew them;* not indeed with the same degree of 

 strength individually in either, but in greater numbers, 



* Note IV. 



