PT. rv. 



PRUNIXG AXD THINNING. 



205 



new deposit of wood and bark over the wounds of trees 

 is the brimming over of tlie descending stream of 

 gro vvth between the wood and the bark, and has nothing 

 to do with the dead wood of the wound, or the dead 

 rim of bark whicih surrounds it. It woukl continue 

 to grow over the dead wood if it were stuck full of 

 nails or tenter-hooks. It does continue to grow over 

 it even when it is rotten ; and when the wood has 

 quite mouldered away, the growth still continues, but, 

 as there is no basis on which to deposit, it curls round 

 on itself. 



Since the publication of the first edition of this 

 treatise, I have found an example which will throw 

 light on what has been stated. 



Plate I. is an engraving of a piece of a board planed Expiana- 

 down to a level with the centre of the pith of the stem, Pifes i. 



-L ' and II. 



and of the pith of a branch. The board is from a 

 Scotch fir cut in Brookwood Park, Hampshire. 



A is intended to represent the upper end of the 

 board, which has been cut across ; B, the lower end. 

 Both of those cross-cut ends are turned so as to face 

 the same way with the side of the board, which is cut 

 lengthways, so that the correspondence of the pith and 

 grain or growths of the ends with those of the side may 

 be easily traced; and the numbering is intended to 

 make this correspondence more clear. In the fir tribe 

 generally, the latest annual shoot is surmounted by a 

 circle of buds, or what is called a whorl of buds, around 

 the leading bud. These whorls of buds become whorls 



