90 
VEGETABLE STRUCTURE. 
Plant; where the Vcflels themfelves being weak, prefs more upon one 
another. 
At Fig. 7'^, is reprefented the mouth of one VefTel, w'ith the ends of 
the woody Fibres. At 74, a fpace filled with the woody matter: at 75 
the fame fpace empty ; and at 76 the fubftance which filled it ; which is 
fiiewn alfo greatly enlarged at 81. 
In a longitudinal fedlion treated the fame way, we fee the Veflels plain- 
ly and difiinflly in their courl'e : they are jointed, as it were, at certain 
diftances, but not cut or pinched in at thofe Joints. The Velfel keeps 
on its courfe ; only there is a Valve at every Joint. This does not open 
in the center, but is loofe for a fmail fpace on one fide, where it is ca- 
pable of being raifed a little, but not of falling inwards or downwards. 
One Bed of thefe Veflels is reprefented at 77 ; and a piece of the whole 
thicknefs, confifling of five Coats covered with two Membranes, at 78 : 
a piece of one Veflel, with its Valve vaftly magnified, at 79 ; and the 
w'oody Fibres which fiipport it at 80. This part is connedted to the Vaf- 
cular Series by fmail oval Veficles or Glands; as that is to the Blea. See 
jy, a a. ^ 
These are minute refearches, but they are important. Juices may 
afcend thefe Veflels, but it is impofliblc they fliould defcend thro’ them : 
cr they may pafs in a regular courfe one w'ay, but not return back. The 
woody Fibres which run up between thefe, have alfo aTmall hollow; but 
the Juice in this is not coloured, as in the Veflels. 
This is the conftrudlion of the Flefli : its courfe we have fliiewn thro’ 
the whole Plant. When it has made a compleat Circle, or Coat in the 
Root, it fends up a portion of irfclf, which forms the Flefliy Subflance 
in the Stalk ; and this at the Head, when the Rinds and Blea have left 
it, going olf in Fibres and Petals, fwells into a fomewhat thicker fubflance, 
arched inwards, and there acquires a firong green. The woodv Fibres 
terminate in this fwoln e.xtremity ; and every Veflel makes a kind of Gland, 
winding about itfelf in various forms, and fliooting forth from the whole 
upper furface of the arch a new Pith ; as this Plefliy Subflance readily does 
in other places. 
This Pith is covered only with an extremely thin portion of the Flefliy 
Subflance, and this breaks away upward into numerous double Threads, 
which are the Filaments. Thele acquire a Coat or Skin, as that fubflance 
does whenever it is expofed to the air : but then, tho’ diverted of its Coat, 
it is flill in the body of the Flower Iheltered from the weather by the 
Petals; 
