VEGETABLE STRUCTURE. 
I2I 
important part of the Plant ; and this is fed from two fources ; thefe 
Leaves as well as the Root. 
The courfe of the Vegetation of the RadiHi, to the prefent period of 
its growth, feems to^ be this. The VelTels of the Root having received 
their due portion of nourifhment, principally at the fpungy ends of the 
Fibres, the whole fubftance of the Embryo has been expanded, and in- 
creafed, fo far as to be terminated by the two large Seminal Leaves. Thus 
much the Juices of the Root have been able to perform : there remains the 
Bud to be fed for rifing to a perfedl Plant ; and there is now an expanfe 
of furface for receiving nourifliinent in a due proportion for that fervice; 
and an apparatus of Veflels for the preparation and didribution of it. A 
certain quantity of Juices is received from the earth ; and in the hours 
of early morning the whole Plant is full of it. As the day rifes, the heat 
evaporates a great deal of this ; and tho' more is raifed, yet Is not the fup- 
ply, perhaps, fuited to the wafte. At evening, when the heat decreafes, 
and the air is full of moifture, thefe fpungy furfaces of the Leaves im- 
bibe that moifture in abundance, which fills all the cells, and gives fuffi- 
cient matter, out of which the Vefiels may elaborate the proper Juices of 
the Plant. Whether the nourifliment rifes from the Root, or is taken in 
at the Leaves, it mufl:, in its courfe, pafs the point *, where is placed 
the rudiment of the Stalk ; and the fwelling there feems appropriated to 
detain it. 
We fee the Membranes of the Leaves are perforated, and their inner 
fubftance is a fpunge, whofe open mouths anfwer to thofe perforations. 
Therefore the moifture which. falls upon thefe Leaves, is eafily received 
into their fubflance. It paffes the outer Bark by means of the oval aper- 
tures ; thefe let it into the fpace between that and the inner Rind. The 
innumerable round apertures in that coat let it thro’ again ; and juft under 
thefe are placed the open mouths of the cells of the Blea, into thefe the 
pure moifture enters. Thefe cells are continued, without any valve, or 
other interruption, thro’ the Blea of the whole; fo that the fluid thus re- 
ceived into them at the Leaves, mixes at once with that of the whole bo- 
dy of the Plant. In the fame manner moifture is taken in at the Roots, 
whofe fpungy heads or extremities are formed of open cells of Blea, co- 
vered only by the two pierced Rinds. 
Thus it appears that moifture is received into the Plant; and fills thofe 
cells of the Blea, which make up the greateft part of the Vegetable fub- 
ftance. About the fides of thefe cells are placed VelTels, with openings 
into them, which have glandular mouths : and thus a portion of this wa- 
VoL. I. R tery 
