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Tab. 39. 

The Vegetation Book III. 
RE 
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 Ajcent of the Sap. 
As to which, I fay, Férf?, That confidering to what heigth and_plen- 
ty, the Sep fometimes afcends; it is not intelligible, how it fhould 
thus afcend, by virtue of any one Part of a Plant, alones that is 
neither by virtue of the Parenchywa, nor by virtue of the Vefels, 
alone. Not by the Parenchywa 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 Gla/s-Pipes immerfed in Water, will give 
it an afcent for fome Inches; yet there isacertain period, according 
to the bore of the Pipe, beyond which it will not rife. We mutt 
therefore joyn the Vefels and the Parenchyma both together in this 
Service ; which we may conceive performed by them in the manner 
following. 
15. g. Let A B bethe Vefel of a Plant. Let CED F be the 
Bladders of the Parenchyma, wherewith, as with fo many little céfferns, 
it isfurrounded. I fay then, that the Sap, in the Pipe BA, would, of 
it {elf, rife but a few Inches ; as fuppofe, from DtoL. But the Blad- 
ders DP, which furround it, being {welled up and turgid with Sap, 
do hereby pref upon it; and fo not only a little contratt its bore, 
but alfo transfufe or {train fome Portion of their Sap thereinto: by 
both which means, the Szp 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 {till forced higher and higher: the Bladders 
of the Parenchyma being, asisfaid, fo many Ciflerns of Liquor, which 
transfufe their repeated Supplies throughout the length of the Pipe. 
So that by the fupply and preffure of the Cifferns or Bladders F D, the 
the Sap rifeth to L; bythe Bladders G_L, it rifes to Ms by the 
Bladders N M, it rifes to 1; by the Bladders O I, it rifestoK 5 by the 
Bladders PK, it rifestoE; and fotothe top ofthe Tree. And thus 
far of the Motioz of the Sap. 

CH AP. 

