E X P L A I N E D BY THE MICROSCOPE. 47
it will therefore become familiar In the colleilions of the curious in Plants. The Rind PLATE
is thicker than in moft things, b and the Bark of a very delicate texture : the Vafa
exteriora are very numerous, tho" not fo large as In many others j their quantity mak- ^
ing amends for their want of fize. Their difpofition feems but irregular j yet a careful
eye will count two ranges of them. The Wood has fewer Sap-VelTels than
ufual i and, what is much more ñrange, they are not perfeftly round : the undulated
outline of all the conftituent parts perhaps prefles upon them. The Pith is immenfe,
-and the Corona fmall: but Nature, confident with herfelf, has given to the cluilers
- of that undulated Ring the fame difpofition within the line, as > the common
Oleander.
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I /Ej
I IV. O f t h e OIF f o r m Bi e .
OF THE Ep h e d r a Di s t i c h a .
We have in this Shrub an inftance of the fportings, as it were, of Nature, in the PLATE'
Blea; perfedly fingular. It is confiderable in quantity; it furrounds the Wood in XXIII.
that kind of undulated line ohferved in the preceding inftance; and to a correft obferver
it appears very diftinSly to be of different textures in its different parts : a line
of VelTels neareft the Wood, and a mere mafs of confufion behind It, toward the Bark.
This will not be difficultly underftood by thofe who have firft acquainted themfelves
with the compoCtion of this part. We have feen it is conftrudled of veffels and an
interflitlal fpunge. All that is fingular here is that the fpunge, nfually placed between
veffel and veffel, is kept feparate, and tlirown behind. A feftion of the Ephedra Is
given in Plate XXIII. and thefe two parts of the Blea are feen at c i. c 2. But the c 1. c 2.
Ephedra gives us much more matter of delight and wonder. With refped to its
Rind and Bark, a i'and the difpofition of the Vafa propria interlora, / ; (for exte- a i f
riora it has none :) they differ not from what is the ufual courfe : but the Wood, d, d
•which is delicately conftruded, £hews the diminution of Sap-Veflels toward the centre
very diftinftly : we even lofe them toward the inner part of the laft grown cifcic
of the feafons. But befide this, that beautiful advance of the Wood toward another
of thofe circles; that which charmed us In the Dog-Rofe, raifes raptures here. W«
fee diftinaiy at e the puihing for a third circle of Wood; and here know how it is i.
formed. The parietes of thefe fruftrums of cones, which in this objed anfwer to the
ellipfes of Wood in the Dog-Rofe, are extended in growth before the matter of the
Wood is formed to fill them. It Is palpable. In a good view of this kind, that they
are well formed, but perfeflly empty. The Corona is very beautifully hollowed; and
in the Pith are palpable Veffels. This is the firft occafion that has offered of naming
them; but we fhall fee them in fome other inftances. , They are the Vafa intima, fo
ftrangely difpofed; this their ftrufture fliews, and the firmnefs, of their contents.
Thefe pierce the Pith in a longitudinal diredlion; or more probably they are primordial
in the ftrufture ©f the Plant, and the Pith is formed around them.
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