^8 
VEGETABLE STRUCTURE. 
C H 'A P. VII. 
Of the Head which terminates the Fibre. ' 
'^I^IIE naked eye may fee this head at the extremity of every Fibre 
plainly, in a Root thus cleaned : and it is impoffible to look on it 
without furprife j it is fo different from what the received opinions fay con- 
cerning the extremities of Fibres. They are fuppofed fmall beyond all 
view, and open. On the contrary, we fee them here enlarged and clofe. 
'Fhe greatert: wonder is, that a thing fo obvious, in a regular e.nquiry, 
fliould have efcaped the obfervation of Naturalifts fo long. The depth of 
Winter is the time to make thefe obfervations ; for the warmth and wet 
of Spring make great changes in the Fibres. 
To the naked eye one of thefe heads appears obtufely conical, larger 
tlian the adjoining part of the Root, and altogether different in colour 
and fubflance ; that is cclourlefs and tranfparenr, this part is opake and 
yellow. No more appears till we cut it open. 
A TRANSVERSE fedfion cf this part fliews a very delicate conflrudlion, 
and very wonderful : but we fliall be more familiar with the parts vvhicli 
compefe it as we advance farther in the Anatomy of the Plant : for tho' 
th.ey he thickened in a peculiar manner, they are the fame feven parts which 
compofe the refl of the Plant. See Fig. lo, i i. — counting from the centre,, 
they are thus difpofed. 
There Is a cavity in the middle of the head, and this is furrounded 
with a thin lining of white Pith, the fame with the Pith of the Stalk or 
Fibre; round this is carried a thick coat of a greenifli fubftance, which 
is the Flcfli of the Plant, the fifth confiituent luhflance of Plants, rec- 
koning from the furfnee ; and near the inner edge of this are placed fix 
conic cluflers of vefftrls, whole points pierce the Pith. Thefe are the 
fixth conflituent fubfiance in all Plants. On the outfide of the coat of 
FleOi runs a vafcular feries ; it appears only in diftindt Dots, but Is com- 
pofed of Veffels inclofed between two Membranes ; this is the fourth 
fubflance in all Plants. (N-er this is a very thick coat of the Blea ; which 
is vvhitifl), and upon this are fpread the two Rinds, the innermofl of which 
thickens at the end of the head, into a kind of jelly. All thefe parts go 
compleatly round this head or extremity of the Fibre, returning upon 
themfelves in fo many arches ; and there is no opening at the end of the 
Fibre j 
