The Vegetation Book III, 
CHAP. VI 
Of the Motions of Trunks, 
S HE Motions alfo of Trunks are various. Princi- 
pally Fours fe. Aftending, Defcending, Horizontal, 
and Spiral. The caufe of the Ajcent of a Plant, isa 
certain Maguetick Corre/pendence betwixt the Aer and 
E the Acr-Veffels of a Plant; the Motion and Tendency 
S h whereof, the whole Plant follows. This I have af- 
ferted, and I think, clearly demonftrated in my 
Firf and Second ‘Books of the Anatomy of Plants. I will here add 
this plain Experiment. 
2. $. Take a Box of Moulds, with a hole bored in the bottom, 
wide enough to admit the stalk ofa Plant, and fet it upon ftilts half 
a yard or more above ground. Then lodg in the Mould fome Plant, 
for Example a Bear, in fuch fort, that the Root of the Bear ftandin; 
in the ‘Moulds may poynt upwards, the stalk towards the ground. 
As the Plant grows, it will follow, that at length the Stalk will rife 
upward, and the Root, on the contrary, arch it elf downward. Which 
evidently fhews, That it is not fufficient, that the. Root hath Barth to 
fhoot into, or that its Motion is only an Appetite of being therein 
lodged, which way foever that be: but that its nature is, though 
within the Earth already, yet to change its Pofítion, and to move Down- 
wards, And fo likewife of the Trunk,, that it rifes,when a Seed {prouts, 
out of the Ground, not meerly becaufe it hath an Appetite of being 
in the open 4er 5 for in this Experiment it is fo already; yet now makes 
a new Motion upwards. 
3. §. BUT although the Natural Motion of the Trunk be to 
Afcend ; yet isit forced oftentimes to Defcend. For the Trumk-Roots 
growing out of fome Plants near the ground, and fhrinking thereinto, 
like fo many Ropes, do pluck the Trw»k annually lower and lower 
into the ground together with them; as may be feen in Scrophularia, 
Facobea, and many other Plants. 
4 $. IF thefe Trumk-Roots break out only about the Lotto of the 
Trunk, asin the aforefaid Plants, then the Trunk gradually Defcends 
into the Earth, and is turned into a Root, But ifitbe very fender, and 
the Trunk-Raots break forth all along it, then it Creeps horizontally 3 
the fiid Roots tethering it, as it trails along, to the ground 5 as in Straw- 
berry, Cinquefoyl, Mint, Scordium, Xe. 
5. $. AS to their Spiral Motion, it is to be noted; That the Wood 
of all Corvolwula's or Winders, {tands more clof and round together in 
or near the Center, thereby making a round, and flender Trunk. To 
the end, it may be more tractable, to the power of the external Motor, 
url ever that be: and alfo more fecure from breaking by its winding 
Motion. 
