JS T I - I E C O N S T R U C T I O N OF TIMBER
P L A T E
X V I .
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A t Plate XVI . F¡g. i. is íliewn a piece o f a young Slioot of Dog-Wood, fplit thro'
f^c two oppofue Buds, to iliew their nature. The part a is the remaining line of the
^'g- ' • Corona j ¿ is the fpace left by the afccnding Bud ; and c are the VeiTels pervading it.
I f now we take a thicker piece of the fame Shrub, and inilead of fplitting i t thro' twa
Buds we carry the knife thro' the ilumps of two Branches, formed by two fuçh Buds in
fome preceding feafon, we find the vertiges of every part remain. Such a piece is repre-
•Fig. 2. a fented at Plate XVI . Fig. 2. Here we fee the line of the Corona (letter a) ilill remain,
but'not fupplied with any new Clufter : andhence we may learn that a fécond Branch can
^ never rife from the fpot, altho' the firft fhould periih by any accident. At b the fpace
c ftill remains J and its Veflels c run tliro' it: but as we carry our eye along the afcendd
ing Shoot, we fee z t d 2. P i th in all refpeíts the fame with that in the center of the
parent Branch. This Pith of the Shoot is not continued from the Pith o f the Branch,
as has been fuppofed ; for they are not, nor ever were, continuous : there is, there
always has been from the beginning, a fpace between them : the fpace exifted even
before the Pith of the Shoot was formed. This Pith therefore was neither derived
from the parent Tree, nor original in the Shoot j but is a mere temporary and
periiliable produtflion, exfudated from the Shoot itfelf, and def ined to ferve its prefent
jjurpofcs, a-d then to periih.
L e t not the newnefs of this opinion make any one paufe to receive it ! Had we never
had.new opinions, old errors would have been immortal : but happily here we may refer
not only to theReafon, but the Eyes! The Hirub is before every onej a penknife
makes the divifion 3 and fcarce a common reading-glafs is necelTary to obferve it.
Altho' in this Shrub the vacant fpace left by the afcending Clufter remains empty,
it has been obferved that there are fome In which that very fpace itfelf becomes, after
a time, filled with a fort of Pith. The Dog-Rofe or Wild-Briar of our hedges gives
an Inftance j and it is always happieft in thefe purfuits when the needful objeits are the
moft familiar.
F i g . 3. A Branch of this, with a Shoot rifing from it, is reprefented at Fig. 3. In this the
a line of the Corona left behind is very diftinátly vifible at a ; and the Pith of the Shoot
b at ¿¡ terminating, as is always the cafe, convexly towards the Branch. Thefe two parts
are very diftinftly known by their green and brown colour j and in the original vac
cancy at í there is found a mafs of a kind of Pith, very coarfe in coraparifon of that
cither in the Branch or in the Shoot,; and perfedlly diftinft from both, communicating
•with neither.
Fig. 4. In the Virginia Creeper, Fig. 4. the very Pith of the Stem is not continuous; but
ends obtufcly upward, and obtufely downward, as in the Branch. And in our own
Vine it is not onjy difcontinuous, but in the moft perfeft ftate of the Tree is inter-
F l g . 5. cepted, a? at Fig. 5.
C H A P .
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