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T H E CONSTRUCTION OF TIMBER
P L A T E There are fome Trees, and a great many herbaceous Plants, in which this part is
continued inward, in form of rays, thro' the Blea, into the Wood; and feems to form
fo many green wedges, fplitting as it were the fiibllance of both thofe parts. It would
be difficult to conceivc how this were done, but that we have feen in the Dog-Rofe
thefe more folid parts are not originally compad; but compofed of feparate picces : between
thefe the. rays of the Bark infinnaCe themfelvcs while they are open, and keep
their places, tho' in a fmaller compafs, always afterwards.
The Sorbus Legitima, or true Service Tree, affords a very ftrong inftance of this:
a piece of a tranfverfe fe£tion of this Tree is given at Plate XIX. This was cut from
a Shoot in its fourth fcafon : we fee plainly at the lines of fcparation the growths of
^ three perfeil feafons: at ^ we fee the adl of growing in a fourth.
The Wood is here, as in the Dog-Rofe, thruft forward and outward into the Bark j
s and that not in a continuous fubftance, as at a, but in detached bodies. They were
c fegments of ellipfes in the Dog-Rofe j here they are cones. The brown Rind c termi-
4 nates their fummits in a regular circle} but the Bark d infinuates itfelf deeply among
them, filling up all the fpace between cone and cone, to their very bafesj and thence
continuing itfelf, tho' in a thinner line, thro' every feafon's growth of the Wood,
down to the very Pith : marking out palpably, by its courfe, the feveral parts which
once were cones of Blea; as the exterior parts, yet retaining the fame form of cones,
•are the true Blea of the Sorbus now: tho' in the courfe of growth their taper ends
have fpread to the fame breadth with their bafcs. Here therefore, as in the Dog-
Rofe, and fome other inftances, the Blea is always a difcontinuous fubftance j tho' in
the generality of Trees it is one foft, but entire ring.
The ufe of this conftruition in the ceconomy of Nature is not difficult to be underftood
: an objedl familiar to me, in infancy, firft threw it upon my mind. In the park
of Sir Francis St. John, at Thorp, near Peterborough, Hood an old Service Tree, perfedly
diverted of its Bark, yet growing and full of vigour. I remember a thoufand
times climbing it when a boy, and to have heard wifer perfons fpeak of it with wonder;
that a Tree thus naked could live. I did not, even at this time, underftand how, till,
taking a cutting from the garden of her Royal Highnefs, this ftruflure prefented itfelf
to me. The coatcf Bark could be fpared, becaufe there were rays of the fame fubftance
within J which anfwered the purpofe. Purfuing this fubjed, I have alfo found
that die Ciftus Laurifolia, which has the fame conftrudion of rays from the Bark, lives
very well when peeled and 'tis familiar that the Plane will do fo. In that Tree alfo
we fee the fame conftruftion, and muft no longer wonder at the fame effed. There are
many other Trees which have fomewhat of this quality; and in examining them I have
found they have all fome degree alfo of this conftruflion j and that^ (fo far as can be
judged) a degree juft anfwering to their more than ufual quality of life.
That Leaves and Branches ihould be produced from a hollow Tree, whofe Wood had
periihed, tho' the Bark was entire, could not appear wonderful to thofe who knew the
nourifhment was from the Bark but that a tree could live whofe Bark was gone, muft
feem, till this was known, almoft a miracle.
C H A P .
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