
















































































ry of . Of the Vegetation Book II. 

formed in the Center, the ficciferous run along thofe likewife (as vo- 
latile salts fooot along the fides of a Glas, or Prof upona Window) 
and fo are, as it were, Incruftate about them ina Rizg. 
How the fe- 36. ¢. SOME OF THE more Attherial and Subtile parts of the Aer, 
veral Parts as they ftream through the Root, -it fhould feem, by a certain Magwi- 
come to be i/e, do gradually difpofe the Aer-Veféls, where there are any {tore 
. of them, into Rays. This Attraétion ( asJ take leave to call it) or 
Mpos c*  Magnetich. power betwixt the Aer and thefe Ve/fels, may be argued, 
From the nature of the Principles common to them both: From the 
EleGral nature of divers other Bodies; the Load-ftone being not the 
(a) Lib. 1. only one which is attractive: And from other Effeéts, both before (2) 
¢.2, §.25. & and hereafter mentioned. Wherefore in the inferiour parts of the 
c.4. Append. Root, they are lefs Regular ; (+) becaufe more remote from the Aer. 
$. 2, 36 And in the upper parts of many Roots, as Gumfery, Borage, Parfnep, 
(b) P.t.04 where thofe that are next the Centre are confufed, or differently 
oe Boo: difpofed ; thofe next the Bargue, and fo nearer the Aer, are poftu- 
»°*"red more Regularly, and ufually into Rays. For the fame reafon it 
may be 3 that even the sap-Veffels in the Barque, as often as the Aer 
Veffels ave more numerous, are ufually difpofed into Rays, as follow- 
ing the direGion of the Aer-Veféls, And chat the Parenchyma of the 
Barque, is difpofed into Diametral Portions : andthat where the Aer 
Veffels are fewer or fmaller, thefe Portions are likewife {maller or none 5 
as in Chervil, Afparagus, Dandelion, Orpine, Biftort, Horfe-Radifh, 
Tab. 7,8, 9, Potato’s, &c. 
&e. 37. §. The faid Atherial parts of the Aer, have a Power over 
the 4er-Yeffels not only thus to Difpofe them 5 but alfo to Sollicite 
and fpread them abroad from the Center towards the Circumference 
of the Root. By which means, thofe Roots which have no Pith in 
(c) P.t. c.g, their lower parts, obtain one in their upper. (¢) And the fame P7th, 
$i. which in the lower part, isratably, {mall, in the upper, is more or 
(d) Ib. $. 4. lefs enlarged. (d) 
38. §. The Spreading of thefe Veffels is varied, not only accor- 
ding to the Force the Aer hath upon them, but alfo their own greater 
or lefS Aptitude to yield thereto. As often therefore, asthey are Slen- 
derer, they will alfo be more Pliable and receflive from the Centre, 
towards the Circumference. Hence, in fuch Roots where they are 
Tb. 2, & 6, Mall, they ftand more diftant ; asin Turnep, Fernfalem Artichoke, Po- 
>” ““tato’s, and others; and fo their Braces are fewer: and in the fame 
Root, where: they are fmaller, their diftance is greater. Befides, in 
thefé {maller Aer-Veffels, the Rings being lefs, and the Spiral Fibres 
whereof they are made, continuing to /hoot 5.the faid Rigs therefore, 
mutt needs be fo many more, as they are fmaller; and fo take up more 
{pace by the length of the Root ; and fo, not being capable of being 
crowded in a right line, every Veffel will be forced to recede to acrooked 
or bowed one. 
39. §. The Sap Veffelsbeing by the Parenchymows Fibres knit to thefé, 
will likewife comply with Their motion, and fpread abroad with them. 
(e) P.t.c.3. Yet being {till {maller (e) and more pliable than the Aer-Veffels, and fo 
$s 16, more yielding to the intercurrent Fibres of the Pzrenchyma, their 
: braced Threds will, fometimes, be much more divaricated, than thofe 
Tab. 6. ofthe Aer-Veffels; asin Ferufalem Artichoke. And becaufethe las 
‘effels. 

