Having examin’d and pursu’d the Degrees of Vegetation in the Seed, we find its two Lobes have here their utmost period; and, that having conveyed their Seminalities into the Radicle and into the Plume; these therefore as the Root and Trunk of the Plant still survive; Of these in their order we next proceed to speak; and first, of the Root: whereof, as well as of the Seed, we must by Dissection inform our selves.
In Dissection of a Root then, we shall find it with the Radicle, as the Parts of an old man with those of a Fœtus, substantially one. The first Part occurring is its skin, the Original whereof is from the Seed: For that extream thin Cuticle which is spred over the Lobes of the Seed, and from thence over the Radicle, upon the shooting of the Radicle into a Root, is co-extended, and becomes its Skin.
The next Part is the Cortical Body; the Original whereof likewise is from the Seed; or the Parenchyma, which is there common both to the Lobes and Radicle, being by Vegetation augmented and prolonged into the Root, is here the Cortical Body, or that which is sometimes called the Barque.
The Contexture of this Cortical Body may be well illustrated by that of a Sponge, being a Body Porous, Dilative, and Pliable. Its Pores, as they are innumerable, so extream small. These Pores are not only susceptive of so much Moisture as to fill, but also to enlarge themselves, and so to dilate the Cortical Body wherein they are; which by the shriv’ling in thereof, by being expos’d to the Air, is also seen. In which dilatation many of its Parts becoming more lax and distant, and none of them suffering a solution of their continuity; ’tis a Body also sufficiently pliable; or, a most exquisitely fine-wrought Sponge.
The Extention of these Pores is much alike both by their length and breadth of the Root; which from the shrinking up of the Cortical Body, in a piece of a cut Root, by the same dimensions, is argu’d.
The proportions of this Cortical Body are various: If thin, ’tis called a Barque; & thought to serve to no other end, than what is usually ascrib’d to it as a Barque; which is a narrow conceit: If a Bulky Body in comparison with that within it, as in the young Roots of Cychory, Asparagus, &c. ’tis here, because the fairest, therefore taken for the prime Part; which, though, as to Medicinal use, it is; yet, as to the private use of the Plant, not so. The Colour hereof, though it be originally white, yet in the continued growth of the Root, divers Tinctures, as yellow in Dock, red in Bistort, are thereinto introduced.
Next within this Part stands the Lignous Body; the Original whereof, as of the two former, is from the Seed; or, the Seminal Roots of both the Lobes, being united in the Radicle, and with its Parenchyma co-extended, is here in the Root the Lignous Body.
The Contexture hereof is, in many of its parts, much more close than that of the Cortical; and their Pores very different: For whereas those of the Cortical are infinitely numerous, these of the Lignous are in comparison, nothing so. But these, although fewer, yet are they many of them more open, fair, and visible: as in a very thin Slice cut athwart the young Root of a Tree, and held up against the Light, is apparent: Yet not in all equally, in Coran-Tree, in Goosberry-Tree, &c. less; in Oak, Plums, and especially Damascens, more; in Elder, Vines, &c. more conspicuous. And as they are different in number and size, so also (whereon the numerousness of the Pores of the Cortical Body principally depends) in their shape. For whereas those of the Cortical Body are extended much alike both by the length and breadth of the Root; these of the Lignous are only by the length; which, especially in Vines and some other Roots, is evident. Of these Pores, ’tis also observable, that although in all places of the Root they are visible, yet most fair and open about the Fibrous Extremities of some Roots (and in many Roots higher) where there is no Pith. These Pores, as they shew in young Roots of Trees, see in Fig. 6, & 7.
This Lignous Body lieth with all its Parts, so far as they are visible, in a Circle or Ring; yet are there divers extream small Fibres thence shooting, usually mixed with the Cortical Body; and by the somewhat different colour of the said Cortical Body where they stand, may be noted these Fibres; the Cortical Body and Skin all together, properly make the Barque.
The proportion betwixt this Lignous Body and the Cortical, is various, as was said; yet in this, constant, sc. that in the fibrous, and smaller Parts of the Root, the Lignous Body is not only in compass, but in quantity the less; running like a slender Wyer or Nerve through the other surrounding it. They stand both together pyramidally, which is most common to Infant-Roots, but also to many other.
The next Part observable in the Root, is the Insertment. The existence hereof, so far as we can yet observe, is sometimes in the Radicle of the Seed it self; I cannot say alwayes. As to its substantial nature, we are more certain; that it is the same with that of the Parenchyma of the Radicle; being alwayes at least augmented, and so, in part, originated from the Cortical Body, and so, at second hand, from the said Parenchyma: For in dissecting a Root, we find, that the Cortical Body doth not only environ the Lignous, but is also wedg’d, and in many pieces inserted into it; and that the said inserted pieces, make not a meer Indenture, but transmit and shoot themselves quite through as far as the Pith; which in a thin Slice cut athwart the Root as so many lines drawn from the Circumference towards the Center, shew themselves. See Fig. 6, & 7.
The Pores of the Insertment are sometimes, at least, extended somewhat more by the breadth of the Root, as about the top of the Root of Borage may be seen; and are thus different from those of the Cortical Body, which are extended by the length and breadth much alike; and from those of the Lignous, being only by its length.
The number and size of these Insertions are various. In Hawthorn, and some others, and especially Willows, they are most extream small; in Cherries and Plums they are large; and in Damascens especially, very fairly apparent. In the Roots of small Plants they are generally more easily discoverable; which may lead to the observation of them in all.
These Insertions, although they are continuous through both the length and breadth of the Root; yet not so in all Parts, but by the several shootings of the Lignous Body are frequently intercepted. For of the Lignous Body it is (here best) observable, That its several shootings, betwixt which the Cortical is inserted, are not throughout the Root wholly distinct; but that all along being enarch’d, the Lignous Body, both in length and breadth, is thus disposed into Braces or Osculations. Betwixt these several shootings of the Lignous Body thus osculated, the Cortical shooting, and being also osculated answerably Brace for Brace, that which I call the Insertment is fram’d thereof.
These Osculations are so made, that the Pores of the Lignous Body, I think, notwithstanding, seldom run one into another; but, for the most part, still keep distinct; in the same manner as some of the Nerves, though they meet, and for some space are associated together, yet ’tis most probable that none of their Fibres are truly inosculated here, but only in the Plexures.
These Osculations of the Lignous Body, and so the interception of the Insertions of the Cortical, are not to be observ’d by the traverse cut of the Root, but by taking off the Barque, or the Cortical Body. In the Roots of Trees, they are generally obscure; but in Plants, often more distinctly apparent; and especially in a Turnep: the appearance whereof, the Cortical Body being stripp’d off, is as a piece of close-wrought Network, fill’d up with the Insertions of the said Cortical Body. See Fig. 8.
The next and last distinct Part of the Root is the Pith. The substantial nature thereof, is, as was said of the Insertment, the same likewise with that of the Parenchyma of the Seed. And according to the best observation we have yet made, ’tis sometimes existent in its Radicle; in which, the two main Branches of the Lobes both meeting, and being osculated together, are thus dispos’d into one round Trunk, and so environing part of the Parenchyma, make thereof a Pith; as in either the Radicle, or the young Root of the great Bean or Lupine, may, I think, be well seen.
But many times the Original hereof is immediately from the Cortical Body. For in dissection of divers Roots both of Trees and Plants, as of Barberry or Mallows, it is observable, that the Cortical Body and Pith are both of them participant of the same Colour; in the Barberry both of them tinged yellow, and in Mallows green. In cutting the smaller Parts of the Roots of many Plants, as of Borage, Mallows, Parsley, Columbine, &c. ’tis also evident, that the Lignous Body is not there in the least Concave, but standeth perfectly in the Center; and that the Insertions being gradually multiplied afterwards, the Pith at length, towards the thicker parts of the Root, shews and enlarges it self. Whence it appears, that in all such Roots, the Pith is not only of the same substantial nature, and by the Insertions doth communicate with the Cortical Body; and that it is also more or less augmented by it; which is true of the Pith of all Roots; but is moreover, by mediation of the said Insertions, wholly originated from it. The various appearances of the Insertions and Pith from the Fibrous Parts to the top of the Root, see in Fig. 9, 10, 11, 12, 13, 14. The Pores of the Lignous Body, entire in the said Fibrous Parts, are best seen when they have lain by a night dry, after cutting.
A farther evidence hereof are the Proportions betwixt the Cortical Body and Pith. For as about the inferiour Parts of the Root, where the Pith is small, the Cortical Body is proportionably great; so about the top, where the Pith is enlarged, the Cortical Body groweth proportionably less, sc. because by its Insertions, ’tis gradually bestowed into the Pith. Likewise the peculiar frame of some Roots, wherein besides the Pith, the Lignous Body being divided into a double Ring, there is also a thick Ring, of a white and soft substance, stands betwixt them; and is nothing else but the Insertions of the Cortical Body collected into the said Ring; but, towards the top of the Root, being inserted again, thus maketh a large and ample Pith; as in Fennel-Roots is seen.
The Pores of the Pith, as those of the Cortical Body, are extended both by the breadth and length of the Root, much alike; yet are they more or less of a greater size than those of the Cortical Body.
The Proportions of the Pith, are various; in Trees, but small; in Plants generally, very fair; in some making by far the greatest part of the Root; as in a Turnep: By reason of the wide circumference whereof, and so the finer Concoction and Assimilation of its Sap; that part which in most old Trunks is a dry and harsh Pith, here proves a tender pleasant meat. The parts of a Turnep in the travers cut see in Fig. 8.
In the Roots of very many Plants, as Turneps, Carrots, &c. the Lignous Body, besides its main utmost Ring, hath divers of its osculated Fibres dispersed throughout the Body of the Pith; sometimes all alike, and sometimes more especially in, or near, its Center; which Fibres, as they run towards the top of the Root, still declining the Center, at last collaterally strike into its Circumference; either all of them, or some few, keeping the Center still; of these principally the Lignous Body of the Trunk is often originated.
These Fibres, although they are so exceeding slender, yet in some Roots, as in that of Flower-de-liz, they are visibly concave, each of them, in their several Cavities also embosoming a very small Pith; the sight whereof, the Root being cut traverse, and laid in a Window for a day or two to dry, may without Glasses be obtained. And this is the general account of the Root; the declaration of the manner of its growth, with the use and service of its several parts, we shall next endeavour.
We say then, that the Radicle being impregnate, and shot into the Moulds, the contiguous moisture, by the Cortical Body, being a Body laxe and Spongy, is easily admitted: Yet not all indiscriminately, but that which is more adapt to pass through the surrounding Cuticle. Which transient Sap, though it thus becomes fine, yet is not simple; but a mixture of Particles, both in respect of those originally in the Root, and amongst themselves, somewhat heterogeneous. And being lodg’d in the Cortical Body moderately laxe, and of a Circular form; the effect will be an easie Fermentation. The Sap fermenting, a separation of Parts will follow; some whereof will be impacted to the Circumference of the Cortical Body, whence the Cuticle becomes a Skin; as we see in the growing of the Coats of Cheeses, of the Skin over divers Liquors, and the like. Whereupon the Sap passing into the Cortical Body, through this, as through a Manica Hippocratis, is still more finely filtred. With which Sap, the Cortical Body being dilated as far as its Tone, without a solution of Continuity will bear; and the supply of the Sap still renew’d; and the purest part, as most apt and ready, recedes, with its due Tinctures, from the said Cortical Body, to the Lignous. Which Lignous Body likewise super-inducing its own proper Tinctures into the said Sap; ’tis now to its highest preparation wrought up, and becomes (as they speak of that of an Animal) the Vegetative Ros or Cambium: the noblest part whereof is at last coagulated in, and assimilated to the like substance with the said Lignous Body. The remainder, though not united to it, yet tinctur’d therein, thus retreats, that is, by the continual appulse of the Sap, is in part carried off into the Cortical Body back again, the Sap whereof it now tinctures into good Aliment: So that whereas before the Cortical Body was only relaxed in its Parts, and so dilated; ’tis now increas’d in real quantity or number of parts, and so is truly nourish’d. And the Cortical Body being saturate with so much of this Vital Sap as serves it self; and the second Remainders discharged thence to the Skin; this also is nourish’d and augmented therewith. So that as in an Animal Body there is no instauration or growth of Parts made by the Bloud only, but the Nervous Liquor is also thereunto assistant; so is it here: the Sap prepared in the Cortical Body, is as the Arterious; and that part thereof prepared by the Lignous, is as the Nervous Liquor; which partly becoming Nutriment to it self, and partly being discharged back into the Cortical Body, and diffusing its Tincture through the Sap there, that to the said Cortical Body and Skin, becomes also true Nutriment, and so they all now grow.
In which growth, a proportion in length and breadth is requisite: which being rated by the benefit of the Plant, both for firm standing and sufficient Sap, must therefore principally be in length. And because it is thus requisite, therefore by the constitution of one of its Parts, sc. the Lignous Body, it is also made necessary. For the Pores hereof, in that they are all extended by its length, the Sap also according to the frame and site of the said Pores will principally move; and that way as its Sap moves, the same way will the generation of its Parts also proceed; sc. by its length. And the Lignous Body first (that is, by a priority causal) moving in length it self; the Cortical also moves therewith. For that which is nourish’d, is extended; but whatever is extended, is mov’d; that therefore which is nourish’d, is mov’d: The Lignous Body then being first nourish’d, ’tis likewise first mov’d, and so becomes and carries in it the Principle of all Vegetative motion in the Cortical; and so they both move in length.
Yet as the Lignous Body is the Principle of Motion in the Cortical; so the Cortical is the Moderator of that in the Lignous: As in Animal Motions, the Principle is from the Nerves; yet being once given to the Muscle or Limb, and that moving proportionably to its structure, the Nerves also are carried in the same motion with it. We suppose therefore, that as the principal motion of the Lignous Body is in length, so is its proper tendency also to ascend: But being much exceeded both in Compass and Quantity by the Cortical as in the smaller parts of the Root it is; it must needs therefore be over-born and governed by it; and so, though not lose its motion, yet make it that way wherein the Cortical Body may be more obedient to it; which will be by descent: Yet both of them being sufficiently pliable, they are thus capable, where the Soyl I may oppose a direct descent, there to divert any way where it is more penetrable, and so to descend obliquely. For the same reason it may also be, that though you set a Bean with the Radicle upward; yet the Radicle, as it shoots, declining also gradually, is thus arch’d in form of an Hook, and so at last descends. For every declination from a perpendicular Line, is a mixed motion betwixt Ascent and Descent; as that of the Radicle also is, and so seeming to be dependent upon the two contrary Tendencies of the Lignous and Cortical Bodies. What may be the cause of those Tendencies (being most probably external, and perhaps something of a Magnetisme) is besides my Task here to enquire.
Now although the Lignous Body, by the position and shape of its Pores, principally groweth in length; yet will it in some degree likewise in breadth: For it cannot be supposed that the purest Sap is all received into the said Pores; but that part thereof likewise, staying about its Superficial parts, is there tinctur’d and agglutinated to them. And because these Pores are prolonged by its length; therefore is it much more laxe and easily divisible that way; as in slitting a Stick, or cleaving of Timber, and in cutting and hewing them athwart is also seen. Whence it comes to pass, that in shooting from the Center towards the Circumference, and there finding more room, its said original Laxity doth easily in divers places now become greater, and at length in open Partments plainly visible. Betwixt which Partments, the cortical Body, being bound in on the one hand, by the surrounding Skin and Moulds, and pressed upon by the Lignous on the other, must needs insert it self, and so move contrary to it, from the Circumference towards the Center: where the said contrary motions continued as begun, they at last meet, unite, and either make or augment the Pith. And thus the Root is fram’d, and the Skin, the cortical and Lignous Bodies, so as is said, hereunto concurrent. We shall next shew the use of the two other Parts, sc. the Insertment and Pith; and first of the Pith.
One true use of the Pith is for the better Advancement of the Sap, whereof we shall speak in the next Chapter. The use we here observe is for the quicker and higher Fermentation of the Sap: For although the Fermentation made in the Cortical Body was well subservient to the first Vegetations, yet those more perfect ones in the Trunk which after follow, require a Body more adapted to it, and that is the Pith; which is so necessary, as not to be only common to, but considerably large in the Roots of most Plants; if not in their inferiour parts, yet at their tops. Where though either deriv’d or amplify’d from the Cortical Body, yet being by its Insertions only, we may therefore suppose, as those, so this, to be more finely constituted. And being also from its co-arctation, while inserted, now free; all its Pores, upon the supply of the Sap, will more or less be amplified: Upon which accounts, the Sap thereinto received, will be more pure, and its fermentation therein more active. And as the Pith is superiour to the Cortical Body by its Constitution, so by its Place. For as it thus stands central, it hath the Lignous Body surrounding it. Now as the Skin is the Fence of the Cortical Body, and that of the Lignous; so is the Lignous again a far more preheminent one unto the Pith; the Sap being here a brisk Liquor, tunn’d up as in a wooden Cask.
And as the Pith subserves the higher Fermentation of the Sap; so do the Insertions its purer Distribution; that separation which the parts of the Sap, by being fermented in the Pith, were dispos’d for; being, upon its entrance into the Insertions, now made: So that as the Skin is a Filtre to the Cortical Body, so are the Insertions a more preheminent one to the Lignous; and as they subserve the purer, so the freer and sufficient distribution of the Sap: For the Root enlarging, and so the Lignous Body growing thicker, although the Cortical and the Pith might supply Sap sufficient to the nutrition of its Parts next adjacent to them; yet those more inward, must needs be scanted of their Aliment; and so, if not quite starv’d, yet be uncapable of equal growth: Whereas the Lignous Body being through its whole breadth frequently disparted, and the Cortical Body inserted through it; the Sap by those Insertions, as the Blood by the disseminations of the Arteries, is freely and sufficiently convey’d to its intimate Parts, even those which from either the cortical Body or the Pith are most remote. Lastly, as the consequent hereof, they are thus assistant to the Latitudinal growth of the Root; as the Lignous Body to its growth in length; so these Insertions of the Cortical, to its better growth in breadth.
Having thus seen the solitary uses of the Several Parts of the Root, we shall lastly propound our Conjectures of that Design whereto they are all together concurrent, and that is the Circulation of the Sap: For the Sap moving through the cortical Body, towards the Pith, through the Insertions thereinto, obtains a pass: Which passage, the superiour Insertions will not favour; because the Pith standing in the same height with them, is there large, the fermenting and course of the Sap quick, and so its opposition strong. But through the inferiour it will much more easily enter; because there, through the smalness of the Pith, the opposition is little, and through the shortness of the Insertions, the way more open. So that though the Sap may meet with some opposition even here, yet here meeting with the least, here it will bestow it self (feeding the Lignous Body in its passage) into the Pith. Into which fresh Sap still entring, this, yet but crude, will subside: that first received and so become a Liquor higher wrought, will more easily mount upwards; and moving in the Pith, as in the Arteria magna, in equal altitude with the more superiour Insertions; the most volatile parts of all will still continue their direct ascent towards the Trunk. But those of a middle nature, and, as not apt to ascend, so being lighter than those beneath them, not to descend neither; they will tend from the Pith towards the Insertions in a motion betwixt both; through which Insertions (feeding the Lignous Body in its passage) it is, by the next subsequent Sap, discharged off into the cortical Body, as into the Vena cava, back again. Wherein, being still pursu’d by fresh Sap from the Center, and more occurring from the Circumference, towards the inferiour Insertions it thus descends; through which, together with part of the Sap afresh imbib’d from the Mould, it re-enters the Pith. From whence, into the Cortical Body, and from thence into the Pith, the cruder part thereof reciprocally is disburs’d; while the most Volatile, not needing the help of a Circulation, more directly ascendeth towards the Trunk.
Having thus declar’d the degrees of Vegetation in the Root; the continuance hereof in the Trunk shall next be shew’d: in order to which, the Parts whereof this likewise is compounded, we shall first observe.
That which without dissection shews it self, is the Coarcture: I cannot say of the Root, nor of the Trunk; but what I chuse here to mention, as standing betwixt them, and so being common to them both; all their Parts being here bound in closer together, as in the tops of the grown Roots of very many Plants, is apparent.
Of the Parts of the Trunk, the first occurring is its Skin: The Formation whereof, is not from the Air, but in the Seed, from whence it is originated; being the production of the Cuticle, there investing the two Lobes and Plume.
The next Part is the Cortical Body; which here in the Trunk is no new substantial formation; but, as is that of the Root, originated from the Parenchyma of the Seed; and is only the increase and augmentation thereof. The Skin, this Cortical Body properly so call’d, and (for the most part) some Fibers of the Lignous mixed herewith, all together make the Barque.
Next, the Lignous Body, which, whether it be visibly divided into many softer Fibres, as in Fennel, and most Plants; or that its parts stand more compact and close, shewing one hard, firm and solid piece, as in Trees; it is in all one and the same Body; and that not formed originally in the Trunk, but in the Seed; being nothing else but the prolongation of the Inner Body distributed in the Lobes and Plume thereof.
Lastly, The Insertions and Pith are here originated likewise from the Plume, as the same in the Root from the Radicle: So that as to their substantial Parts, the Lobes of the Seed, the Radicle and Plume, the Root and Trunk are all one.
Yet some things are more fairly observable in the Trunk. First, the Latitudinal shootings of the Lignous Body, which in Trunks of several years growth, are visible in so many Rings, as is commonly known: For several young Fibres of the Lignous Body, as in the Root, so here, shooting into the Cortical one year, and the spaces betwixt them being after fill’d up with more (I think not till) the next, at length they become altogether a firm compact Ring; the perfection of one Ring, and the ground-work of another being thus made concomitantly.
From these Annual younger Fibres it is, that although the Cortical Body and Pith are both of the same substantial nature, and their Pores little different; yet whereas the Pith, which the first year is green, and of all the Parts the fullest of Sap, becomes afterwards white and dry; the Cortical Body, on the contrary, so long as the Tree grows, ever keepeth green and moist, sc. because the said Fibers annually shoot into, and so communicate with it.
The Pores likewise of the Lignous Body, many of them in well-grown Timber, as in Oaken boards, are very conspicuous, in cutting both lengthwise and traverse; they very seldom run one into another, but keep, like so many several Vessels, all along distinct; as by cutting, and so following any one of them as far as you please, for a Foot or half a Yard, or more together, may be observ’d.
These greater Pores, though in Wainscot, Tables, and the like, where they have lain long open, they are but meer Vacuities, and so would be thought to contain only Sap in the Tree, and afterwards only Air; yet upon a fresh cut, each of them may be seen fill’d up with a light and spongie Body, which by Glasses, and even by the bare eye, appears to be a perfect Pith; sometimes entire, and sometimes more or less broken.
Besides these, there are a lesser sort; which, by the help of a Microscope, also appear, if not to be fill’d up with a Pith, yet to contain certain light and filmy parts, more or fewer, of a Pithy nature within them.
And these are all the Pores the best Glasses, which, (when upon these Enquiries) we had at hand, would shew us. But the Learned and most Ingenious Naturalist Mr. Hook sheweth us moreover, besides these, a third, and yet smaller sort; the description whereof I find he hath given us amongst his Microscopical Observations. Of these Pores (as a confirmation of what, in the Second Chapter, I have said of the Pores of the Lignous Body in general) he also demonstrates; that they are all continuous and prolonged by the length of the Trunk; as are the greater ones; the Experiment whereof he imparteth to be, by filling up, suppose in a piece of Char-coal, all the said Pores with Mercury; which appears to pass quite through them, in that by a very good Glass it is visible in their Orifices at both ends; and without a Glass, by the weight of the Coal alone, is also manifest.
Upon farther Enquiry, I likewise find, that the Pores of the Lignous Body in the Trunk of Plants, which at first only supposed, by the help of good Glasses are very fairly visible; each Fibre being perforated by 30, 50, 100, or hundreds of Pores. Or what I think is the truest notion of them, that each Fibre, though it seem to the bare eye to be but one, yet is indeed a great number of Fibres together; every Pore being not meerly a space betwixt the several pores of the Wood, but the Concave of a Fiber: So that if it be asked, what all that part of a Vegetable, either Plant or Tree, which is properly call’d the woody part; what all that is, I suppose, that is nothing else but a Cluster of innumerable and most extraordinary small Vessels or concave Fibres. See Fig. 15.
Next the Insertions of the Cortical Body, which in the Trunk of a Tree saw’d athwart, are plainly discerned as they run from the Circumference toward the Center; the whole Body of the Tree being visibly compounded of two distinct Substances, that of the several Rings, and that of the Insertions, running cross; shewing that in some resemblance in a Plain, which the Lines of Latitude and of the Meridian do in a Globe. See Fig. 16.
These Insertions are likewise very conspicuous in Sawing of Trees length-wayes into Boards, and those plain’d, and wrought into Leaves for Tables, Wainscot, Trenchers, and the like. In all which, as in course Trenchers made of Beech, and Tables of Oak, there are many parts which have a greater smoothness than the rest; and are so many inserted pieces of the Cortical Body; which by reason of those of the Lignous, seem to be discontinuous; although in the Trunk they are extended throughout its Breadth.
These Insertions, although as is said, of a quite distinct substance from the Lignous Body, and so no where truly incorporated with it, yet being they are in all parts, the one as the Warp, the other as the Woof, mutually braced and inter-woven together, they thus constitute one strong and firmly coherent Body.
As the Pores are greater or less, so are the Insertions also: To the bare eye usually the greater only are discernable: But through an indifferent Microscope there are others also, much more both numerous and small, distinctly apparent. So that, I think, we may observe, that as the grand Pith of the Trunk communicates with, and is augmented by the greater Insertions; so is the Pith of each greater Pore originated from the less; and those (at least) pithy parts in the Midling Pores, from others still less; and suppose, that the least of all are so far intruded into the smallest Pores, as only just to cause a kind of roughness on their concave sides, and no more; to what end shall be said. See Fig. 17.
In none of all these Pores can we observe any thing which may have the true nature and use of Valves, which is easily to admit that, to which they will by no means allow a regress. And their non-existence is enough evident, from what in the first Chapter we have said of the Lobes of the Seed: in whose Seminal Root, were there any Valves, it could not be, that by a contrary course of the Sap, they should ever grow; which yet, where-ever they turn into Dissimilar Leaves, they do. Or if we consider the growth of the Root, which oftentimes is upward and downward both at once.
The Insertions here in the Trunk give us likewise a sight of the position of their Pores. For in a plained piece of Oak, as in Wainscot, Tables, &c. besides the larger Pores of the Lignous Body, which run by the length of the Trunk; the Tract likewise of those of the Insertions may be observed to be made by the breadth, and so directly cross. Nor are they continuous as those of the Lignous Body, but very short, as those both of the Cortical Body and Pith, with which the Insertions, as to their substance are congenerous. Yet they all stand so together, as to be plainly ranked in even Lines or Rows throughout the breadth of the Trunk: As the Tract of these Pores appear to the naked Eye, see in Fig. 18. By the best Microscope I have at hand, I can only observe the Ranks of the Pores; not the Pores themselves, saving here and there one; wherefore I have not describ’d them.
The Pores of the Pith likewise being larger here in the Trunk, are better observable than in the Root: the width whereof, in comparison with their sides so exquisitely thin, may by an Honey-Comb be grosly exemplified; and is that also which the vast disproportion betwixt the Bulk and weight of a dry Pith doth enough declare. In the Trunks of some Plants, they are so ample and transparent, that in cutting both by the length and breadth of the Pith, some of them, even to the bare eye would seem to be considerably extended by the length of the said Pith; which once I also thought they were, and that only the rest of them were but short and discontinuous, and as ’tis said, somewhat answerable to the Cells of an Honey-Comb. This was the nearest we could come to them, by conjecture, and the assistance of the best Glasses we then had by us, when upon enquiry into the nature of the Pith: But that Worthy Person newly mentioned Mr. Hooke sheweth us, that the Pores of the Pith, particularly of Elder-Pith, so far as they are visible, are all alike discontinuous; and that the Pith is nothing else (to use his own words) but an heap of Bubbles.
Besides what this Observation informs us of here, it farther confirms what in the second Chapter we have said of the Original of the Pith and Cortical Body, and of the sameness of both their natures with the Parenchyma of the Seed. For, upon farther enquiry with better Glasses, I find, that the Parenchyma of the Plume and Radicle, and even of the Lobes themselves, though not so apparently, is nothing else but a Mass of Bubbles.
In the Piths of many Plants, the greater Pores have some of them lesser ones within them, and some of them are divided with cross Membranes: And betwixt their several sides, have, I think, other smaller Pores visibly interjected. However, that they are all permeable, is most certain. They stand together not indeterminately, but in even Ranks or Trains; as those of the Insertions by the breadth, so these by the length of the Trunk. And thus far there is a general corresponding betwixt the part of the Root and Trunk: Yet are there some considerable Disparities betwixt them; wherein, and how they come to pass, and to what especial use and end, shall next be said.
We say then, that the Sap being in the Root by Filtrations, Fermentations (and in what Roots needful, perhaps by Circulation also) duly prepar’d; the prime part thereof passing through the intermediate Coarcture, in due moderation and purity is entertain’d at last into the Trunk. And the Sap of the Trunk being purer and more volatile, and so it self apt to ascend; the motion of the Trunk likewise will be more noble, receiving a disposition and tendency to ascend therewith. And what by the Sap the Trunk is in part dispos’d to, by the respective position and quantity of its Parts it is effectually enabled. For whereas in the Root the Lignous Body being in proportion with the Cortical, but little, and all lying close within its Center; it must therefore needs be under its controul: on the contrary, being here comparatively of greater quantity, and also more dilated, and having divers of its Branches standing more abroad towards the Circumference, as both in the Leaves and Body of the young Trunk and Plume, is seen; it will in its own tendency to ascend, reduce the Cortical Body to a compliance with it.
And the Trunk thus standing from under the restraint of the Mould in the open Air, the disposition of its Parts originally different from that of the Parts in the Root will not only be continued, but improved: For by the force and pressure of the Sap in its collateral Motion, the Lignous Body will now more freely and farther be dilated. And this being dilated, the Cortical Body also, must needs be inserted; and is therefore in proportion alwayes more or less smaller here in the Trunk, than in the Root. And as the Cortical Body lessens, so the Pith will be enlarged, and by the same proportion is here greater. And the Pith being enlarged it self, its Pores (the Lignous Body, upon its dilatation, as it were tentering and stretching out all their sides) must needs likewise be enlarged with it, and accordingly are ever greater in the Pith of the Trunk, than of the Root. And the dilatation of the Lignous Body still continued, it follows, that whereas the Pith descendent in the Root, is not only in proportion less and less, but also in the smaller extremities thereof, and sometimes higher altogether absent: Contrariwise, in the Trunk it is not only continued to its top, but also there in proportion equally ample with what it is in any other inferiour part.
But although the openness of the Ayr permitting be alwayes alike; yet the Energy of the Sap effecting; being different; as therefore that doth, the dilatation of the Trunk will also vary. If that be less, so is this; as in the Trunks of most Trees: If that be greater, so is this; as in Plants is common; the Lignous Body being usually so far dilated, that the utmost shootings thereof may easily be seen to jut out, and adjoyn to the Skin. And if the Sap be still of greater energy, it so far dilates the Lignous Body, as not only to amplifie the Pith and all its Pores; but also so far to stretch them out, as to make them tear. Whereupon either running again into the Cortical Body, or shrinking up towards it, the Trunk thus sometimes becomes an hollow Stalk, the Pith being wholly, or in part voyded. But generally it keeps entire; and where it doth, the same proportion and respect to the Lignous and Cortical Bodies, as is said. The Consequences of all which will be, the strength of the Trunk, the security and plenty of the Sap, its Fermentation will be quicker, its Distribution more effectual, and its Advancement more sufficient.
First, the erect growth and strength of the Trunk; this being by the position of its several parts effected: For besides the slendering of the Trunk still towards the top, the Circumferential position of the Lignous Body likewise is, and that eminently hereunto subservient: So that as the Lignous Body in the smaller part of the Root standing Central, we may thence conceive and see their pliableness to any oblique motion; so here, on the contrary, the Lignous Body standing wide, it thus becomes the strength of the Trunk, and most advantageous to its perpendicular growth. We see the same Design in Bones and Feathers: The strongest Bones, as those in the Legs, are hollow. Now should we suppose the same Bone to be contracted into a Solid Body, although now it would be no heavier, and in that respect, as apt for motion; yet would it have far less strength, than as it is dilated to a Circumferential posture. And so for Quills, which, for the same Reasons, in subserviency to flight, we see how exceeding light they are, and yet, in comparison with the thinness of their Body, how very strong: We see it not only in Nature, but Art. For hence it is that Joyners and Carpenters unite and set together their Timber-pieces and several Works oftentimes with double Joynts; which, although they are no thicker than a single one might be made, yet standing at a distance, have a greater strength than that could have. And the same Architecture will have the same use in the Trunks of Plants, in most whereof ’tis very apparent; as for instance, in Corn: For Nature designing its Sap a great Ascent for its higher maturity, hath given it a tall Trunk; but to prevent its ravenous despoiling either of the Ear or Soyl; although it be tall, yet are its sides but thin: and because again, it should grow not only tall and thriftily, but for avoiding propping up, strongly too; therefore, as its height is over-proportioned to the thinness of its sides, so is its Circumference also; being so far dilated as to parallel a Quill it self. Besides the position of the Lignous Body within the compass of a Ring, we see some shootings thereof often standing beyond the Circumference of the said Ring, making sometimes a triangular, oftner a quadrangular Body of the Trunk; to the end, that the Ring being but thin, and not self-sufficient, these, like Splinters to Bones, might add strength and stability to it.
Next, the security and plenty of the Sap. For should the Lignous Body, as it doth in the Root, its smaller parts, stand Central here also, and so the Cortical wholly surround it: the greater part of the Sap would thus be more immediately expos’d to the Sun and ayr; and being lodg’d in a laxe Body, by them continually be prey’d upon, and as fast as supplied to the Trunk, be exhausted. Whereas the Pith standing in the Center, the Sap therein being not only most remote from the Ayr and Sun, but by the Barque, and especially the Wood, being also surrounded and doubly immur’d, will very securely and copiously be conveyed to all the Collateral parts, and (as shall be said how) the top of the Trunk.
And the Sap by the amplitude, and great porosity of the Pith being herein more copious, its Fermentation also will be quicker; which we see in all Liquors by standing in a greater quantity together, proceeds more kindly: And being tunn’d up within the Wood, is at the same time not only secur’d from loss, but all extream mutations, the Day being thus not too hot, nor the Night too cold for it.
And the Fermentation hereof being quicker, its motion also will be stronger, and its distribution more effectual, not only to the dilatation of the Trunk, but likewise the shooting out of the Branches. Whence it is, that in the Bodies of Trees, the Barque of it self, though it be sappy, and many Fibres of the Lignous Body mixed with it, yet seldom sendeth forth any; and that in Plants, those with the least Pith (other advantages not supplying this defect) have the fewest or smallest Branches, or other collateral Growths: and that Corn, which hath no Pith, hath neither any Branches.
Lastly, the Advancement of the Sap will hence also be more ready and sufficient. For the understanding where, and how, we suppose that in all Trunks whatsoever there are two parts joyntly hereunto subservient. In some the Lignous Body and the Cortical, as in older Trunks, the Pith being either excluded or dried: But in most, principally the Lignous Body and Pith; as in most Annual Growths of Trees; but especially Plants, where the Cortical Body is usually much and often wholly inserted.
Of the Lignous body it is so apparent by its Pores, or rather by its Vessels, that we need no farther evidence. For to what end are Vessels but for the conveyance of Liquor? And is that also, which upon cutting the young Branch of a Sappy Tree or Plant, by an accurate and steady view may be observed. But when I say the Pores of the Lignous Body, I mean principally them of the younger shootings, both those which make the new Ring, and those which are mixed with the Cortical Body in the Barque: that which ascendeth by the Pores of the older Wood, being probably, because in less quantity, more in form of a Vapour, than a Liquor. Yet that which drenching into the sides of its Pores, is with all thereunto sufficient Aliment; as we see Orpine, Onions, &c. only standing in a moyster Ayr will often grow; And being likewise in part supplied by the Insertions from the younger Shoots: But especially, because as it is but little, so it serveth only for the growth of the said Older Wood, and no more; whereas the more copious Aliment ascendent by the younger Shoots, subserves not only their own growth, but the generation of others; and is besides with that in the Cortical Body the Fountain of Perspirations, which we know even in Animals are much more abundant than the Nutritive parts; and doubtless in a Vegetable are still much more.
But these Pores, although they are a free and open way to the ascending Sap; yet that meer Pores or Vessels should be able of themselves to advance the Sap with that speed, strength & plenty, and to that height, as is necessary, cannot probably be supposed. It follows then, that herein we must grant the Pith a joynt service. And why else in the smaller parts of the Root, where the Pith is often wanting, are the Pores there greater? Why is the Pith in all primitive growths the most Sappy part, why hath it so great a stock of Sap, if not after due maturation within it self still to be disbursed into the Fibres of the Lignous Body? Why are the annual growths of all both Plants and Trees with great Piths, the quickest and the longest? But how are the Pores of the Pith permeable? That they are so, both from their being capable of a repletion with Sap, and of being again wholly emptied of it, and again, instead thereof fill’d with Ayr, is as certain as that they are Pores. That they are permeable, by the breadth, appears from the dilatation of the Lignous Body, and from the production of Branches, as hath been, and shall hereafter be said. And how else is there a Communion betwixt this and the Cortical Body? That they are so also, by the length, is probable, because by the best Microscope we cannot yet observ, that they are visibly more open by the breadth, than by the length. And withal are ranked by the length, as those of the Insertions by the breadth of the Trunk. But if you set a piece of dry Elder-Pith in some tinged Liquor, why then doth it not penetrate the Pores, so as to ascend through the Body of the Pith? The plain reason is, because they are all fill’d with Ayr. Whereas the Pith in a Vegetating Plant, as its Parts or Pores are still generated, they are at the same time also fill’d with Sap; which, as ’tis gradually spent, is still repair’d by more succeeding, and so the Ayr still kept out; as in all primitive growths, and the Pith of Elder it self: Yet the same Pith, by reason of the following Winter, wanting a more copious and quick supply of Sap, thus once become, ever after keeps dry. And since in the aforesaid Trial the Liquor only ascends by the sides of the Pith, that is of its broken Pores, we should thence by the same reason conclude that they are not penetrable by the breadth neither, and so no way; and then it need not be ask’d what would follow. But certainly the Sap in the Pores of the Pith is discharged and repaired every moment, as by its shriv’ling up; upon cutting the Plant is evident.
We suppose then, that as the Sap ascendeth into the Trunk by the Lignous Body, so partly also by the Pith. For a piece of Cotton with one end immers’d in some tinged Liquor, and with the other erect above, though it will not imbibe the Liquor so far as to over-run at the top, yet so as to advance towards it, it will; so here, the Pith being a porous and spongy Body, and in its Vegetating state its Pores also permeable, as a curious Filtre of Natures own contrivance, it thus advanceth, or as people use to say, sucks up the Sap. Yet as it is seen of the Liquor in the Cotton; so likewise are we to suppose it of the Sap in the Pith; that though it riseth up for some way, yet is their some term, beyond which it riseth not, and towards which the motion of the ascending Sap is more and more broken, weak and slow, and so the quantity thereof less and less. But because the Sap moveth not only by the length, but breadth of the Pith; at the same time therefore as it partly ascendeth by the Pith, it is likewise in part pressed into the Lignous Body or into its Pores. And since the motion of the Sap by the breadth of the Pith not being far continued, and but collateral, is more prone and easie than the perpendicular, or by its length; it therefore follows, that the collateral motion of the Sap, at such a height or part of the Pith, will be equally strong with the perpendicular at another part, though somewhat beneath it; and that where the perpendicular is more broken and weak, the collateral will be less; and consequently where the perpendicular tendency of the Sap hath its term, the collateral tendency thereof, and so its pressure into the Pores of the Lignous Body will still continue. Through which, in that they are small, and so their sides almost contiguous, the Sap as fast as pressed into them will easily run up; as betwixt the two halves of a Stick first slit, and then tied somewhat loosely together, may also any Liquor be observed to do. And the sides of the said Pores being not smooth, but by the intrusion of the smallest insertions made somewhat rough; by that means the higher and more facile ascent of the Sap therein will farther be promoted. By all which Advantages the facility and strength of that ascent will be continued higher in the said Pores than in the Pith. Yet since this also, as well as that in the Pith will have its term; the Sap, although got thus far, would yet at last be stagnant, or at least its ascent be very sparing, slow and feeble, if not some way or other re-inforced. Wherefore, as the Sap moving by the breadth of the Pith, presseth thence into the Pores of the Lignous Body; so having well fill’d these, is in part by the same Collateral motion disbursed back into a yet higher Region of the Pith. By which partly, and partly by that portion of the Sap, which in its perpendicular ascent was before lodged therein; ’tis thus here, as in any inferiour place equally repleat. Whereupon the force and vigour of the perpendicular motion of the Sap herein will likewise be renew’d; and so its Collateral motion also, and so its pressure into the Pores of the Lignous Body, and consequently its ascent therein; and so by a pressure from these into the Pith, and from the Pith into these reciprocally carried on, a most ready and copious ascent of the Sap will be continued from the bottom to the top, though of the highest Trunk.
The distinct Parts whereof these are constituted, are the same with those of the Trunk, and but the continuation of them.
Trunk-Roots are of two kinds: Of the one, are those that vegetate by a direct descent: The place of their Eruption is sometimes all along the Trunk; as in Mint, &c. Sometimes only at its utmost point, as in the Bramble.
The other sort are such as neither ascend nor descend, but shoot forth at right Angles with the Trunk; which therefore, though as to their Office, they are true Roots, yet as to their Nature, they area Middle thing betwixt a Root and a Trunk.
Claspers, though they are but of one kind, yet their nature is double; not a mean betwixt that of the Root and that of the Trunk, but a compound of both; as in their Circumvolutions, wherein they often mutually ascend and descend, is seen.
The use of these Parts may be observed as the Trunk mounts, or as it trails. In the mounting of the Trunk, they are for support and supply: For support, we see the Claspers of Vines; the Branches whereof being very long, fragile and slender, unless by their Claspers they were mutually contain’d together, they must needs by their own weight, and that of their Fruit, undecently fall, and be also liable to frequent breaking. So that the whole care is divided betwixt the Gardener and Nature; the Gardener with his Ligaments of Leather secures the main Branches; and Nature with these of her own finding, secures the less. Their Conveniency to which end, is seen in their Circumvolutions, a motion not proper to any other Part: As also in their toughness or strength, though much more slender than the Branches whereon they are appendent.
For Supply, we see the Trunk-Roots of Ivy: For mounting very high, and being of a closer Constitution than that of a Vine, the Sap could not be sufficiently supplied to the upper Sprouts, unless these to the Mother-Root were joyntly assistant. Yet serve they for support likewise; whence they shoot out, not as in Cresses, Brook-lime, &c. reciprocally on each side, but commonly all in one; that so they may be fastened at the nearest hand.
In the Trailing of the Trunk, they serve for stabiliment, propagation and shade. For stabiliment, we see the Claspers of Cucumbers: For the Trunk and Branches being long and fragile, the Brushes of the Winds would injuriously hoise them to and fro, to the dammage both of themselves and their tender Fruit, were they not by these Ligaments brought to good Association and Settlement.
As for this end, so for Propagation, we see the Trunk-Roots of Camomile. Whence we have the reason of the common observation, that it grows better by being trod upon: the Mould, where too laxe, being thus made to lie more conveniently about the said Trunk-Roots newly bedded therein; and is that which we see also effected in Rowling of Corn.
For both these ends, we see the Trunk-Roots of Strawberries; as also for shade; for in that we see all Strawberries delight; and by the trailing of the Plant is well obtain’d: So that as we are wont to tangle the Twigs of Trees together to make an Arbour Artificial; the same is here done to make a Natural one; as likewise by the Claspers of Cucumbers: For the Branches of the one by the Linking of their Claspers, and of the other by the Tethering of their Trunk-Roots, being couched together; their tender fruits thus lie under the Umbrage of a Bower made of their own Leaves.
The Parts of the Germen and Branch, are the same with those of the Trunk; the same Skin, Cortical and Lignous Bodies, Insertment and Pith, hereinto propagated, and distinctly observable herein.
For upon Enquiry into the Original of a Branch or Germen, it appears, That it is not from the Superficies of the Trunk, but so deep, as to take with the Cortical, the Lignous Body into it self; and that not only from its Circumference, but (so as to take the Pith in also) from its Inner or Central parts. Divers whereof may commonly be seen to shoot out into the Pith; from which Shoots the surrounding and more superiour Germens are originated; in like manner as the Lignous Body of the Trunk is sometimes principally from those Fibrous Shoots which run along the Pith in the Root.
The manner wherein usually the Germen and Branch are fram’d, is briefly thus: The Sap (as is said, Chap. 3.) mounting in the Trunk, will not only by its length, but by its breadth also, through the Insertions partly move. Yet, its Particles being not all alike qualified, in different degrees: Some are more gross and sluggish; of which we have the formation of a Circle of Wood only; or of an Annual Ring: Others are more brisk; and by these we have the Germen propagated. For by the vigour of their own motion from the Center, they impress an equal tendency on some of the inner parts of the Lignous Body next adjacent to the Pith, to move with them. And since the Lignous Body is not entire, but frequently disparted; through these dispartments, the said interiour Parts, upon their Nutrition, actually shoot; not only towards the Circumference, so as to make part of a Ring, but even beyond it, in order to the production of a Germen. And the Lignous Body thus moving, and carrying the Cortical along with it; they both make a force upon the Skin: Yet their motion being most even and gradual, that force is such likewise; not to cause the least breach of its parts, but gently to carry it on with themselves; and so partly by the extension of its already existent parts, as of those of Gold in drawing of Guilded Wyer; and partly by the accretion of new ones, as in the enlarging of a Bubble above the Surface of the Water, it is extended with them to their utmost growth. In which growth, the Germen being prolonged, and so displaying its several parts, as when a Prospective or Telescope is drawn out, thus becomes a Branch.
The same way as the propagation of the Parts of a Germen is contriv’d is its due nutrition also: For being originated from the inner part of the Lignous Body, ’tis nourished with the best fermented Sap in the Trunk, sc. that next adjacent to it in the Pith. Besides, since all its Parts, upon their shooting forth, divaricate from their perpendicular, to a cross Line, as these and the other grow and thrive together, bind and throng each other into a Knot; through which Knot the Sap being strain’d, ’tis thus in due moderation & purity delivered up into the Branch.
And for Knots, they are so necessary, as to be seen not only where collateral Branches put forth; but in such Plants also as shoot up in one single Trunk; as in Corn; wherein, as they make for the strength of the Trunk; so by so many percolations as they are Knots, for the transmission of the Sap more and more refined towards the Ear. So that the two general uses of Knots are for firmer standing, and finer growth.
Lastly, as the due Formation and Nutrition of the Germen are provided for, so is its security also; which both in its position upon the Trunk, and that of its Parts among themselves may be observed. The position of its Parts shall be considered in speaking of the Leaf. As to its standing in the trunk, ’tis alwayes betwixt the trunk or Elder Branch, and the Basis of the Stalk of the Leaf; whereby it is not only guarded from the Injuries of any contingent Violence, but also from the more piercing assaults of the Cold, so long till in time ’tis grown, as larger, so more hardy. The manner and uses of the position of every Germen, considered as after it becomes a Branch, hath already been by the Ingenious Mr. Sharrock very well observed; to whom I refer.
Upon the prolongation of the Germen into a Branch, its Leaves are thus display’d. The Parts whereof are substantially the same with those of a Branch: For the Skin of the Leaf is only the ampliation of that of the Branch; being partly by the accretion of new, & partly the extention of its already existent parts (dilated as in making of Leaf-Gold) into its present breadth. The Fibres or Nerves dispersed through the Leaf, are only the Ramifications of the Branch’s Wood, or Lignous Body. The Parenchyma of the Leaf which lies betwixt the Nerves, and as in Gentlewomens Needle-works, fills all up, is nothing else but the continuations of the Cortical Body, or inner part of the Barque from the Branch into it self, as in most Plants with a fat Leaf, may easily be seen.
The Fibres of the Leaf neither shoot out of the Branch nor Trunk, nor stand in the Stalk, in an even Line; but alwayes in either an Angular or Circular posture, and usually making either a Triangle, or a Semi-Circle, or Cord of a Circle; as in Cycory, Endive, Cabbage, &c. may be observed: And if the Leaf have but one main Nerve, that also is postur’d in a Circular or Lunar Figure; as in Mint and others. The usual number of these Nerves or Fibres is 3, 5, or 7. See the Figures from 20, to 29.
The reason of the said Positions of the Fibres in the Stalk of the Leaf, is for its more erect growth, and greater strength; which, were the position of the said Fibres in an even Line, and so the Stalk it self, as well as the Leaf flat, must needs have been defective; as from what we have said of the Circumferential posture of the Lignous Body in the Trunk, we may better conceive.
As likewise for the security of its Sap: For by this means it is, that the several Fibres, and especially the main or middle Fibre of the Leaf, together with a considerable part of the Cortical Body, are so disposed of, as to jut out, not from its upper, but its back, or nether plain. Whence the whole Leaf, reclining backward, becomes a Canopy to them, defending them from those Injuries which from colder Blasts, or an hotter Sun, they might otherwise sustain. So that by a mutual benefit, as these give suck to all the Leaf, so that again protection to these.
These Fibres are likewise the immediate visible Cause of the shape of the Leaf: For if the nethermost Fibre or Fibres in the Stalk be in proportion greater, the Leaf is long, as in Endive, Cycory, and others: If all of a more equal size, it spreads rounder, as in Ivy, Doves-foot, Colts foot, &c. And although a Dock-Leaf be very long, whose Fibres notwithstanding, as they stand higher in the Stalk, are disposed into a Circle all of an equal size; yet herein a peculiar fibre, standing in the Center betwixt the rest, and running through the length of the Leaf, may be observed.
In correspondence also to the size and shape of these Fibres, is the Leaf flat: In that either they are very small, or if larger, yet they never make an entire Circle or Ring; but either half of one, as in Borage, or at most three parts of one, as in Mullen, may be seen. For if either they were so big, as to contain; or so entire, as perfectly to include a Pith, the Energy of the Sap in that Pith, would cause the said Lignous Ring to shoot forth on every side, as it doth in the Root or Trunk: But the said Fibres being not figur’d into an entire Ring, but so as to be open; on that hand therefore where open, they cannot shoot any thing directly from themselves, because there they have nothing to shoot; and the Sap having also a free vent through the said opening, against that part therefore which is thereunto opposite, it can have no force; and so neither will they shoot forth on that hand; and so will they consequently that way only which the force of the Sap directs, which is only on the right and left.
The several Fibres in the Stalk, are all inosculated in the Leaf, with very many Sub-divisions; according as these Fibres are inosculated near, or at, or shoot directly to the edge of the Leaf, is it even or scallop’d. Where these Inosculations are not made, there we have no Leaves, but only a company of Ramulets, as in Fennel.