Í 
F nn... E 3 SS 8 BS 
126 The Vegetation Book III. Va 
alike freely. Which, as well as divers other Experiments -plainly 
fhews, That in the Sap-Veféls of a Plant, there are no Valves. 
13. $. FROM what we have now above,and elfewhere formerly 
faid, we may alfo underftand the manner of the Afcent of the Sap. 
As towhich, I fay, Fír/f, That confidering to what heigth and plen- ‘ 
ty, the Sap fometimes afcends; it is not intelligible, how it fhould 
thus afcend, by virtue of any one, Part of a Plant, alonez that is 
neither by virtue of the Parenchymra, nor by virtue of the VÁRls, 
alone. ` Not by the -Parenchyma alone. For this, as it hath the Na- 
ture of a Sponge or Filtre, to fuck up the Sap; fo likewife, to fuck 
it up but toa certain heigth, as perhaps, about an Inch, or two, and 
no more. 
14. $. Nor by the Vefels alone, for the fame reafon. For all- 
though we fee, that {mall Glaß-Pipes immerfed in Water, will give 
it an afcent for fome Inches 5 yet there is a certain: period, accordin; 
to the bore of the Pipe, beyond which it will not rife. We mul 
therefore joyn the Vefels and the Parenchyma both together in this 
Service 5 which we may conceive performed by them in the manner 
following. 
15. $. Let A B bethe Vefel of a Plant. Let CED F be the 
Bladders of the Parenchyma, wherewith, as with fo many little cifferns, 
Tab. 39. it isfurrounded. I. fay then, that the Sap, in the Pipe B A, would, of 
it felf, rife but a few Inches 5 as fuppofe, from D toL. But the Blad- 
ders D P, which furround it, being fwelled up and turgid with Sap, 
do hereby prefs upon it; and fo not only a little contract its bore, 
but alfo transfufe or ftrain fome Portion of their. sap thereinto: by 
both which means, the Sap will be forced to rife higher therein. And 
the faid Pipe or. Vefel being all along furrounded by the like Blad- 
ders; the Sap therein, is fill forced higher and higher: the Bladders 
of the:Parenchyma being, as is faid, fo many Ciferns of Liquor, which 
transfufe their repeated Supplies throughout the length of the Pipe. 
So that by the fupply and preflure of the Cifferns or Bladders F D, the 
the. Sap rifeth to L; by the Bladders Q. L, it rifes to M3 by the 
Bladders N M, it rifes to 15 by the Bladders O I, it rifes toK ; by the 
Bladders PK, it rifestoE5 and fotothe top ofthe Tree. And thus 
far of the Motion of the Sap, 
