144 
VEGETABLE STRUCTUTvE. 
cuter fabftances, they become continuations of the body of the Root itfelf, 
except in regard to tlie Pith ; each forming a Pith of its own. 
This is the conflruftlon of the Root; and in tliis it is eafy to fee that 
the Flefliy Subdance is the eficntial part ; the Seat of Vegetative Life, and 
fource of all the reft ; iF we begin to trace it at the very crown of the 
Root, Fig. 2, f t, we fee it form a thick yellovvifti line, whicli l-es under 
three coverings ; and purities Its courle to the very firther end of the Root, 
g g : it does not terminate or break off there, as has been fuppofed by 
former Writers, but purfucs an uninterrupted courle round that end, and 
returns up to the Crown, f f, again : it increafes in'thicknefs as it rifes to- 
ward the Crown ; juft as it decreafed going the other way from tlience. 
The rcafon of tlfis is plain : it is entire at the Crown ; but in its courfe 
toward the bale of the Root, it fends off Veifels to the other Coats ; and 
Pith, and the Fibres alfo for drawing nourilhment. Thefe being a part of 
its fubftance, reduce all the way its thicknefs, till at the bafe, g g, it is a 
mere line, yet perfedlly diftindb. This has not been heretofore obferved ; 
but a great deal depends upon it. 
The Seed of the Plant firft forms this Root: its Heart, or Plantule, as 
people have idly called it, is an original annular piece of the Fleftiy Sub- 
Itancc, from the Stalk of tlie parent Plant: this fwclling with the moi- 
flure, and growing from the warmth, in the bofom of the earth, firft: ex- 
tends itfelf in bignefs, ftiooting a Pith within, and Coats without, for its 
defence ; and while th’S is doing, Fibres, h h, are alfo fent out to feek 
diftant nouriftiment ; and Radical Leaves, i i, to aflift: the courfe of the 
Juices. The origin of the Fibres we have fecn : and thefe compleat what 
IS called the Root. Tlie rife of the Radical Leaves, the fecond part of the 
Plant, we are now to examine. 
We have feen, in other inftanccs, the outer Coat of the Root continu- 
ed up in form of the outer Bark of the Stalk ; but here it is otherwife. 
In the generality of Plants the Stalk confifts, like the Root, of feven parts 
or lubftances : laut in this the entire Stalk is compoFed only of fix. It rifes 
fiom within the crown of the Root; and no outer Rind is continued to it. 
The Footftalks of the Radical Leaves, i i, have the fame ftrudture with 
this Stem : and they are thus formed. 
The outer Bark of the Root terminates abfclutely at the Crown, f f. 
As mere a film as this feems, powerful Glaftes (hew it to be Vafcular, as 
in other Plants ; and it has two Membranes, containing the VeffeL. W'e 
fee this in its termination in the part juft named. Its office is to cover 
the Root only ; and that being performed, it fplits into a kind of fcales, e e, 
at 
