of Plants. 
And this being dilated, the Cortical Body alfo, muft needs be 
and is therefore in proportion always, more or lef, fmaller 
in the Truzk , than in the Root. And as the Cortical Body leffens, 
T 
] m IL 
fo Pith will be enlarged, and by the fame proportion is here 
greater, Andthe Pith being enlarged it elf, its Pores (the Lignous 
Body, upon its dilatation, as it were tentering and ftretching out all 
the 
fides) muft needs likewife be enlarged with it; and according- 
ly, are ever greater in the Pith of the Trunk, than of the Rovt. 
And the dilatation of the Ligwous Body ftill continued, it follows, 
that whereas the Pith defcendent in the Root, is not only in propor- 
tion lef and leß, but alfo in the fmaller extremities thereof, and fome- 
times higher, altogether abfent : Contrariwife, in the Trunk, it ds 
not only continued to its top and fmalleft Twigs, but alfo there, in 
proportion, equally ample with what it is in any other inferiour 
part. 
: 23. $. But although the openne of the Aer permitting, be all- 
ways alike 5 yet the Energy of the Sup efletting, being different; as 
therefore that doth, the dilatation of the Trunk, will alo vary. If 
that be lefs, fo is this; as in the Trunks of molt Trees : If that be 
ater, fo thiss asin Herbs is common; the Lignons Body being ufa- 
ally fo far dilated, that the utmofé Shootings thereof may cafıly be 
feen to jut out, and adjoyn to the Ski». And if the Sap be (till of 
greater energy, it fo far dilates the Lignous Body, as not only to am- 
plifie the Pith and all its Pores; but alfo P far to ftretch them out, 
as to make them tear. Whereupon either running again into the 
Cortical Body, or (hrinking up towards it, the Truk thus fometimes 
becomes an hallow Stalk, the Pith being wholly, or in part voided. 
But generally it keeps entire; and where it doth, the fame proporti- 
on and refpect to the Ligzous and Cortical Bodies, as is faid. The 
Confequences of all which will be, the Strength of the Trunk, the Se- 
curity and Plenty of the Sap, its Fermentation will be quicker, its Dj- 
firibution more effe&ual, and its Advancement more fùfficient. 
24. $. Firft, the Ere& Growth and Strength of the Trunks this 
being, by the pofition of its feveral Parts, effected : for befides the flen- 
dering of the Trunk (till towards the top, the Circumferential pofition 
of the Lignous Body, likewife is, and that eminently, hereunto fübfervi- 
ent. So that as the Z 
ignous, Body, inthe finaller parts, of the Rost 
ftanding Central, we may thence conceive and fee their pliableneß to 
any oblique motion 5 fo here, on the contrary, the Lignous Body ftan- 
ding wide, it thus becomes the Strength of the Truk, and moft ad- 
vantageous to its Perpendicular Growth. We fee the fame Defign in 
Bones and Feathers: The ftrongeft Bones, as thofe in the Legs, are 
hollow. Now fhould we fappofe the fame Boxe, to be contraded in- 
fo a Solid; although now it would be no heavier, and in that re- 
fpect, as apt for motion ; yet would it have far leß ftrength, than as 
its Parts are dilated to a Circ 1mferential pofkare. And fo for Quills, 
for the fame R fons, ia fübfervieney to flying, as they are ex- 
parifon with the thinnefs of their Sides, they 
and much leapt to bend, than if contracted into a 
We fee it not only in Nature, but Art. For hence it 
rs and Carpenters unite and fet together their Timber- 
sand feveral Works oftentimes with double Joynts ; which, al- 
though 
