FORMATION OF THE BARK OF TREES. 247 



each other, as when detached ; and through this substance 



the ramifications of the vessels of the new bark extended 



themselves, appearing to receive their direction from the fluid 



sap, which descended from the bark of the young shoots, and 



not to be, in any degree, influenced in their course by the 



direction taken by the cortical and alburnous vessels of the 



preceding year. 



Whenever the vessels of the bark, which proceeded from Cortical vessels 

 , . ' . , , . A meeting form, 



different points, met each other, an interwoven texture was an interwoven 



produced, and the alburnum beneath acquired a similar or- texture, 

 ganization; and the same thing occurs, and is productive of 

 very important effects, in the ordinary course of the growth 

 of trees. The bark of the principal stem, and of every la- Junction of la- 

 teral branch, contains very numerous vessels, which are tera ranc es * 

 charged with the descending true sap; and at the juncture 

 of the lateral branch with the stem, these vessels meet each 

 other. A kind of pedestal of alburnum, the texture of 

 which is much interwoven, is in consequence formed round 

 the base of the lateral branch ; which thus becomes firmly 

 united to the tree. This pedestal, though apparently a part 

 of the branch, derives a large portion of the matter, annually 

 added to it, from the cortical vessels of the principal stem ; 

 and thence, in the event of the death of the lateral branch, 

 it always continues to live. But it not unfrequently happens, Weak when 



that a lateral branch forms a very acute angle with the fornun £ a very 



acute angle, 

 principal stem, and, in this case, the bark between them be- 

 comes compressed and inactive; no pedestal is in conse- 

 quence formed, and the attachment of such a branch to the 

 stem becomes extremely feeble and insecure*. Instead of 



* The advantages, which may be obtained by pruning timber trees ju- Advantages of 

 diciously, appear to be very little known. I have endeavoured to as- P r0 P erl y prun- 

 certain the practicability of giving to trees such forms as will render their in * timber 

 timber more advantageously convertible to naval or other purposes, trees. 

 The success of the experiments, on small trees, has been complete, and 

 the results perfectly consistent, in every case, with the theory I have 

 endeavoured to support in former memoirs ; and I am confident, that by 

 appropriate management, the trunks and branches of growing trees may 

 be moulded into the various forms best adapted to the use of the ship- 

 builder •, and that the growth of the trees may at the same time be ren- 

 dered considerably more rapid, without any expense or temporary loss to 

 the proprietor. 



