Part 3

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_.

CHAP. III.

_Of 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.