5 ' TH E CONS T RUC T IO N OF TIMBER
XXXVI? 'PP™'"'"' 'liclitrtoceous kinds as to be dmof t all Pi th, we fee them in the fub-
• ftance of the Bark, at b, extremely large, and placed fo near, that the circumference,
inftcad of three or four in a quarter, here contains fix or feven; the Plant hnving
from twenty-four to twenty-eight in the circle of the Bark. In the ref.nous, and in
fome of the gummy Trees, we always iind thefe Veffels filled with their proper juiccs.
' In this Shrub I have, on the contrary, always found them empty, c : but near them,
d and behind them, are difpofed other Velfels, d, large, tho' not like thcfc, and cloft
arranged in a regular conneiled line : thefe are at all times filled with a peculiar juice,
tough, fragrant, firm, and coloured. Nature has not allotted the fingle feries of
Vafa interiora, as by an inviolable law belonging to all Plants, we ftal! fee them, in
a fucceeding inftance, in much greater quantity : and here, tho' it be lefs dift ina or
obvious, the cafe is juf t the fame.
The farther particularities in the Tanacetum Fruticans are not a few, or flight ones :
< glands, ,, in the form of hairs, hang on its outer Rind ; a thing common in the herf
baccous tribe, tho' it be lefs fo in trees. The Blea, / forms an undulated line, of a
g clofe texture; and immediately within that Hands what there is of Wood, ^ ; 'a thin
loofe circle, formed not into cones, but oval bodies, and feparated by the matter of
the parietes. run out into a kind of fpunge, and forming a regular circle under the
Blea. The Corona, h, is a circle of more than ufual circumference i and Nature
' has allotted it accordingly to be very thin : and the Pith, i, which is of the fimpleft
kind, by far exceeds in quantity all the reft together.
I I I . O r THE VAEIOOS SERIES or THE VASA PROPRIA INTERIORA
I N T H E P I N U S CEMSRA.
P L A T E If the place of thefe fopernumerary Veffels. in the preceding inftance. could lead
XXXVIIl. „s , ij j y ^^^^ jj^j ¡^ ^^^^^^ ^^ ^^^^
terlora, what was there conjeaure here amounts to certainty. The Pinus Cembiii,
a ftaion of which is given in Plate XXXVI I I . befide its fingle range of immenfe Vafa
a exteriora. a, placed in the ufual way in its thick Bark, has two or more lefs orderly
ranges of Vefl"els, palpably of the fame nature : and even befide thefe there is a ring
b of fmaller Veffels, I, furrounding, at a little diftance, each of the larger. 'Tis
happy that in this Tree the juice which fills the great Vafa propria is fo pure and fine a
turpentine, fo abundant in its quantity, and fo peculiar in its fmell, that there could
need no more or better teft whether thefe other Vefibls were of the fame kind, than
•whether they did or did not carry the fame peculiar j uice. The tip of a pencil touched
upon their open mouths determines this perfeflly.
c What there is farther obfervablc in this T r e e , is. that the Rind, c, is thick, which indeed
d is lefs unufual in the refinous Trees than thofe with watery juices; that the Bark, d, is
very thick and very delicately formed, the cells being more d i f t ina and yet with thinner
, / edges than in moft T r e e s : the Blea, is a firm, dulky, compaa circle. The Wood, f , on
the other hand, is tranfparent to a degree fcarce feen in any other Tree, except thofe of its
g own genus, and pierced with a confiderable number of Sap-Veffels. In thefe. during
the