OCR Text |
Show SE SE —_— Thus, e.g. a Pea or Bean being committed to the Ground, is firft found to cleave into two Parts, which are, as it were, two Leaves or Lobes of the Placenta, and in the Fiffure appears a Point, which fhoots out a Root downwards, and a Bud upwards; the firft {preading itfelf in the Soil to catch the Moi- Side, e.g. the radual Part is unfol ded by th ie groffer, and all on the other by morefubr ile Juices, If the Plantule then be inver ted, and the Root a-top, as it ftill imbibes the groffer and heavier Juices, and the Stem the lighter ; the Point of Separation being conce iy’d Point of a Lever, the Root mutt as thefix’d defcend, and at the fture thereof; and the latter mounting into the Air, and becoming the Stem or Body of fame time that the volati le Juices imthe new Plant. bibed by the Stem, tend to make it mount. It is very remarkable, how the Plumule or Thus is thelittle Plant turn’d on its fix’d Point future Stem fhould always get uppermoft, and of Separation , till it be perfe@ly ere, the Radule or Rovt be turn’d downwards, and The Plant thus erected, M. Paren t accounts this too perpendicularly to the Horizon: And for the Stem’s conti nuing to rife in the virtual not only this, but if by any external Means Direction, thus: The nutritious Juice being the Stem be diverted from this Perpendicular, arriv’'d at the Extr emity of a rifing Stulk and and bent, for Inftance, towards the Earth, in- there fixing into a veget ible Subftance, the {tead of perfevering in that Direction, it makes Weight of the Atmoiphere muft determine it an Angle or Elbow, and redreffes itfelf. to fix in a virtual Pofition 3 fo that the Stalk The fame is obferv’d in Trees, €¢. blown will have acquir’d a new Part of Perpendicudown with their Rocts by the Wind; or in larity over the reft ; juftas ina Candle, which thofe planted in Pots, upon turning the Pot held any how obliquely to the Horizon, the on one Side. Flame will {till continue vertical by the Preffure Now the Seed from which a Plant arifts, of the Air. being the Plant itfelf in Miniature, ’tis eafy to The new Drops of Juice that fucce ed, will fuppofe, that, if it be depofited inthe Ground follow the fame Direétion; and as all together with the Plumule perpendicularly upward, form theS tem, that muft of Courfe bevertical, and the Radule downward, the Ditpofition unlefs fome particular Circumftance intervene, 2 fhould be maintain’d inits future Growth. And, that But it is known, that Seeds fown either of wife obferv’d, whereas the Branches are likeas much as poffible, to affea themfelves, or by the Help of Man, fall ar Perpe ndicularity; infomuch, that tho’ theybe Random, or among an infinite Number of forc’d to fhoot out of the Stem horizontally , Situations of the Plumule, ©&c. the perpen- yet in their Progrefs they ere@ themfelves: M. dicular ong upwards is but one; {0 that Parent {olves this from the vertical ‘Tend in ency all the reft, “tis neceffary the Stem and Root of the nutritious Juice up the Stem ; for the do each make a Bend to be able the one to Juice being receiy’d in this Direétion into the emerge directly upwards, the other new tender Bud, finds, at firft, little Refilt wards. Now what Force is it that downeffects ance; and afterwards, as the Branch grows this Change, which jis certainly an Action of firmer, it furnithes a longer Arm of a Lever Violence ? to act by. M. Dodart, who firft took Notice of Mr. Afrue accounts for the perpendicu the Phenomenon, accounts for it by fuppofing lar Afcent of the Stems, and their redrefling themFibres of the Stem of fuch a Nature, the as to felves when bent, on thefe two Principles. contract and fhorten by the Heat of the Sun, 1. That the nutritious Juice arifes from the and lengthen by the Moifture of the Earth ; Root tothe Topin longitudinal Tubes and onthe contrary, the Fibres of the , paralRoot lel to the Side of the Plant, which commu nito contract by the Moifture of the Earth, and cate cither by themfélves, or by means ofother lengthen by the Heat of the Sun. horizontal Tubes, Proceeding from the CirOnthis Principle, when the Piantuyle is in- cumference of the Plant, and terminated in verted, and the Root a-top, the Fibres of the Root being unequally expos’d to the Moifture, the Pith, 2. That Fluids contain’d in ‘Tubes, either viz. the lower Parts more than the upper, parallel or oblique to the Horizon, gravitate the lower will contract ; and this Contraétion on the lower Part of the Tubes, and not all be promoted by the lengthening of the from the Aétion of the Sun. The upper on the upper. ConfeFrom henceit eafily follows, that in a Plant, quence whereof will be, the Roots recoiling, pofited either obliquelyor parallel infinuating farther into the Earth, to the Horiand getting zon, the nutritious Juice will aét more on the beneath the Body of the Seed. lower Part of the Canals than the upper ; and Ina Word, the Earth draws the Root to- bythat means infinuate more into the ward itfelf, and the Sun promotes its Canals Defcent ; communicating therewith, on the contrary, the Sun draws and be collected up the Plume, more copionfly there in : Thus and the Earth, in fome meafure, the Pat mm fends it to- lower Side will a@ more on the lower } wards the fame. and will receive more Accretion, and M. De Ja Hire accounts for the be mo fame Per- nourifh’d than thofe on the pendicularity, by only conceiving upper: ‘The Con! the Root quence whereof muft be, that the Extre mity to draw a coarfer and heavier Juice; and ofthe Plant will be oblig’d to bend upward. the Stem a finer and More volatile one: In the Plantule therefore The fame Principle brings the Seed into its we may conceive a due Situationat firft : In a Bean planted upfid Point of Separation ; fuch e as that all on one down the , Plume and Radicle are eafi w r ceiv’d, with the naked Eye, to fhoot at firft dire€tly for about an Inch ; but thenceforth they begin to bend, the one downward, and the other upward. The two Placentule or Cotyledones of a Seed a Cafe to this little tender tule or Point, covering it up, fheltering it from Injuries, and feeding it from their own proper Subftance, which the Plantyle receives and draws to itfelf, by an infinite Numberof little Filaments or Ramifications, called Funes or Navel-ftrings, whichit fends into the Bodyof the Placenta. Now when the Seed is committed to the Earth, the Pla ftill adheres to the Embryo for fome time, guards it from the Accefs of noxious Colds, &c. and even prepares and purifies the cruder Juice the Plant is to receive from the Earth, byftraining it, &e. through s own Body. Chis it continues to do, till the Placentula alittle enur’d to its new Element, andits bly fix’d in the Ground, andfitto ‘ice thereof, it then perifhes, and the Plant maybefaid to be deliver’d: So that Nature obferves the fame Method in Plar in’d in Fruits, asin Animals in the Mo- irprizing how manySorts of Seeds good for feveral Years, and rev Faculty 3 where many ot grow when theyare more which is in a great meafure more or lefs with ir outward Coveré Seeds of Cucumbers which have thick, horny s, do continue good eight or ten and R Yy irnip, Rape, &c. with fe Coats, tho’ they are the others) yec aboundwill keep g 1 three whereas the Seeds of moft part growing ; : | as ity often in one Year, but do feldom remain 1 longer than two Year Seeds are preferv’d beft if kept in the Pods or Hufks v y grew; fo that wh would fend § to a diftant Country, { | take Care theyare full rip gather’d, and that they ar Pods or Husks, and no t up too om the Air, which is abfolutely necefto maintain the Prin Y in a lef ; a Seeds fromthe Phials, Ifo from the Bags, and fowed them at the e@ time, and upon the fame Bed, wher had an equal Advantage of Sun, The Contequence of this was, al Seeds which I took out of the Bags remely well; but thofe which were kept in the Phials did not one come up: After which, I fow’d the remaining Part of the Seeds in the Phials, but had not one fingle Plant from the Whole; whereas thofe preferv’d in the Bags grew very well both the fecond and third Years: And this Experiment was afterwards try’d by one of my particular Friends, with whom the Effe& was the fame as with me: So that thofe Perfons who fend Seeds to a diftant Countt y> thould never put them up in Glafles, as hath by fomeunfkilful Perfons been direéted. The Earth, which is the natural Nurfe to all Seeds, will preferve them much Jonger than any other Body, provided they are buried fo deep as to be beyond the Influence of Sua and Showers, where by they are prevented from vegetating. I have known. Seeds of feveral Plants remain bury’d three Feet deep above twenty Years, and when turn’d up to as well as fireth Seeds ; the Air, have grown and a particular Friend of mine, fhew’d mea as cover’d with CornSpot of Ground whi Sallet, the Seeds of which he affur’d me had been bury’d thirty-two Years in that Place ; nto the Air, were as and when turn’d up productive as new Seeds, A Methed for rai hard Coats that have been impoffible, to be l Juch Seeds bh have In the Year 1724, I had a Parcel of frefh Cocoa-Nuts given me, which was bro. ght over from Barbadoes: Part of thefe Nuts I divelted of their outward Coat or Hufk, and the other Part I left intire, as I receiv’d them. Both thefe Parcels I planted in large Pots, fill’d with good frefh Earth, and plung’d the Pots into Hot-beds made of Tanner’s Bark, giving them gentle and frequent Waterings, as the Earth in the Pots feem?d to re quire, but had not one out of the whole Number made any Attempt to fhoot, as I could perceive5 and upon taking them out of the Pots, I found the y were rotten. About four Months after I receiv’d another frefh Parcel of Cocoa-Nuts from Barbadoes, which I treated in another manner: From of thefe I cut off the Outer-Coat or and the other Part I left intire, as before: But fuy pofing it was ing the other Horfe-dung Earth abot owing to my plant Parcel in Pots, that they did not fucceed, I made a freth Hot-bed (with it over with freth ches thick, in which I ving, as before, to } Moifture, as alfo n an equal Temper of led to do by a Thermo>: Ufe of Hot-beds; but |