Chapter V: Book 4: Anatomy of Leaves, Flowers, Fruits and Seeds (4)

♦ An Account of the Growth of the _Root_. ♦ 23. §. I 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 adapted 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: the purest part, as most apt and ready, recedes, with its due _Tinctures_, from the said _Cortical Body_, to all the parts of the _Lignous_; both those mixed with the _Barque_, and those lying within it. 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 Spirit_ is also thereunto assistant; so is it here: the _Sap_ prepared in the _Cortical Body_, is as the _Bloud_, and that part thereof prepared by the _Lignous_, is as the _Nervous Spirit_; 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.

24. §. 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.

25. §. 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 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 a kind of _Magnetisme_) I shall not make my Task here to enquire.

26. §. 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 it is 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, thereunto concurrent. We shall next shew the use of the two other _Parts_, _sc._ the _Insertment_ and _Pith_; and first of the _Pith_.

27. §. ONE true use of the _Pith_ is for the better Advancement of the _Sap_, whereof I shall speak in the next Chapter. The use I 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 coarctation, 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_.

28. §. 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 starved, 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 _Bloud_ by the disseminations of the _Arteries_, is freely and sufficiently convey’d to its intimate Parts, even those, which from either the _Barque_ or from 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.

29. §. Having thus seen the solitary uses of the Several _Parts_ of the _Root_, I shall lastly propound my Conjectures of that Design whereto they are altogether concurrent, and that is the _Circulation_ of the _Sap_.

30. §. That the _Sap_ hath a Double, and so a _Circular_ Motion, in the _Root_; is probable, from the proper Motion of the _Root_, and from its Office. From its Motion, which is Descent: for which, the _Sap_ must likewise, some where, have such a Motion proper to it. From its Office, which is, To feed the _Trunk_: for which, the _Sap_ must also, in some _Part_ or other, have a more especial Motion of Ascent.

31. §. We may therefore suppose, That the _Sap_ moving in the _Barque_, towards the _Pith_, through the _Insertions_, thereinto obtains a pass, Which passage, the upper _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 lower it will much more easily enter; because there, from the smallness of the _Pith_, the opposition is little, and from the shortness of the _Insertions_, the way more open. So that the _Sap_ here meeting with the least opposition, here it will bestow it self (feeding the _Lignous Body_ in its passage) into the _Pith_. Into which, fresh _Sap_ still entring, this being yet but crude, will subside: that first receiv’d, and so become a Liquor higher wrought, will more easily mount upwards. And moving in the _Pith_, especially in the _Sap-Fibers_ there dispers’d, as in the _Arterys_, in equal altitude with the upper-_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_, and so into the _Sap-Fibres_ themselves, as into the _Veins_, back again. Wherein, being still pursu’d by fresh _Sap_ from the Center, and more occurring from the Circumference, towards the lower _Insertions_, it thus descends. Through which, together with part of the _Sap_ afresh imbib’d from the Earth, it re-enters the _Pith_. From whence, into the _Cortical Body_, and from thence into the _Pith_, the cruder part thereof, is reciprocally 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.

1. §. That which without dissection shews it self, is the _Coarcture_: I cannot say of the _Root_, nor of the _Trunk_; but what I choose 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.

2. §. 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_.

3. §. 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 _Plume_ in the _Seed_; and is only the increase and augmentation thereof. ♦ _Tab. 3. f. 1, & 4._ ♦ The _Skin_, this _Cortical Body_ or _Parenchyma_, and (for the most part) some Fibers of the _Lignous_ mixed herewith, altogether make the _Barque_.

4. §. Next, the _Lignous Body_, which, whether it be visibly divided into many softer _Fibers_ or small _Threads_, as in the _Bean_, _Fennel_, and most _Herbs_; ♦ _Tab. 3. f. 1._ ♦ 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 _Seminal Root_ distributed in the _Lobes_ and _Plume_ thereof.

5. §. 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.

6. §. 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 apparent in so many _Rings_, as is commonly known. For several young Fibers of the _Lignous Body_, ♦ _Tab. 3. f. 5, & 8._ ♦ as in the _Root_, so here, shooting in 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.

7. §. From these Annual younger _Fibers_ 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 _Sap-Fibers_, annually grow therein, and so communicate with it.

8. §. 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, if ever, run one into another, but keep, like so many several _Vessels_, all along distinct; ♦ _Tab. 3. f. 2. & 3._ ♦ 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. And so, the like, in any _Cane_.

9. §. Besides these, there are a lesser sort; which, by the help only of a good _Spectacle Glass_ may be observ’d.

10. §. And these are all the _Pores_ visible without a _Microscope_. The use of which, excepting in some few particulars, I have purposely omitted in this first _Book_. ♦ Micrography. ♦ Mr. _Hook_ sheweth us, besides these, a third, and yet smaller Sort; and (as a confirmation of what, in the Second _Chapter_, ♦ _C. 2. §. 8._ ♦ I have said of the _Pores_ of the _Lignous Body_ in general) that they are all continuous and prolonged by the length of the _Trunk_, as are the greater ones: whereof he maketh Experiment, by filling up, 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. All these I have seen, with the help of a good _Microscope_, in several sorts of _Woods_. ♦ _Tab. 3. f. 7._ ♦ As they all appeare in a piece of _Oak_, cut transversely, See _Tab. 3._

11. §. Upon further Enquiry, I likewise find, That the _Pores_ of the _Lignous Body_ in the _Trunks_ of _Herbs_, which at first I only supposed, by the help of good _Glasses_, are very fairly visible: each _Fibre_ being sometimes 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; and every _Pore_, being not meerly a space betwixt the several parts of the Wood, but the _Concave_ of a _Fiber_. So that if it be asked, what all that Part of a _Plant_, either _Herb_ or _Tree_, which is properly called the _Woody-Part_; what all that is, I suppose, That it is nothing else but a _Cluster_ of innumerable and most extraordinary small _Vessels_ or _Concave Fibers_: ♦ _Tab. 3. f. 6._ ♦ as in a Slice of the Trunk of _Burdock_ is apparent.

12. §. 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_, ♦ _Tab. 3. f. 5. & 8._ ♦ which the _Lines_ of _Latitude_ and of the _Meridian_ do in a _Globe_. The entrance of the _Insertions_ into the _Wood_, is also, upon striping off the Barque, very apparent; as in the same _Fig. 8._

13. §. These _Insertions_ are likewise very conspicuous in Sawing of _Trees_ length-ways 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; ♦ _Tab. 3. f. 2. & Tab. 4. f. 1._ ♦ and are so many _inserted Pieces_ of the _Cortical Body_; which being by those of the _Lignous_, frequently intercepted, seem to be discontinuous, although in the _Trunk_ they are really extended, in continued Plates, throughout its Breadth.

14. §. 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 _interwoven_ together, they thus constitute one strong and firmly coherent Body; ♦ _Tab. 4. f. 1._ ♦ as the Timber of any _Tree_.

15. §. As the Pores or Vessels 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, ♦ _Tab. 3. f. 7._ ♦ as in a transverse piece of _Oak_.

16. §. In none of all the _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 nonexistence is enough evident, from what in the first _Chapter_ ♦ _C. 1. §. 42._ ♦ 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. And being cut transversely, will bleed, both the same ways, with equal freedom.

17. §. 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_; ♦ _Tab. 3. f. 2._ ♦ 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 those _Pores_ appears to the naked Eye, see in _Tab. 3. Fig. 9._ The _Pores_ themselves may be seen in the _Root_ of a _Vine_ described and figured in the Second _Book_, as it appears through a good _Microscope_. ♦ _Tab. 17._ ♦

18. §. 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 _Hony-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 through the transparency of the _Skins_ by which they are bounded, or of which they consist, would seem to be considerably extended by the length of the _Pith_; but are really discontinuous and short, and as ’tis said, somewhat answerable to the _Cells_ of an _Hony-Comb_. This is the nearest we can come to them, by the bare Eye without the assistance of a good _Microscope_. Mr. _Hook_ sheweth in his _Micrography_, 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 but (as he calls them) an heap of _Bubbles_. Although, in regard they are not fluid, but fixed Parts, I shall choose rather to call them, _Bladders_. As they appear through a good _Glass_, in a piece of _Burdock_, See in _Tab. 3._ ♦ _Tab. 3. f. 6._ ♦ But a more particular Description of the _Sizes_, _Figures_, and admirable _Textures_ hereof, I have given in several places in the following _Books_.

19. §. Besides what this Observation informs us of here, it farther confirms what in the Second _Chapter_ ♦ _C. 2. §. 3, 16, 17._ ♦ 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_: which is nothing else but a Mass of _Bladders_; ♦ _C. 1. §. 18. & Tab. 1. f. 9._ ♦ as in the First _Chapter_ hath been said.

20. §. In the _Piths_ of many _Plants_, the greater _Pores_ or _Bladders_ 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 _Bladders_ visibly interjected. However, that they are all permeable, is most certain. They stand together not confusedly, 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 parts 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.

♦ An Account of the _Growth_ of the _Trunk_. ♦ 21. §. 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 dipos’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 _magnetical_ tendency to _ascend_, reduce the _Cortical Body_ to a compliance with it.

22. §. And the _Trunk_ thus standing from under the restraint of the Ground 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 always, 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 and smallest _Twigs_, but also there, in proportion, equally ample with what it is in any other inferiour part.

23. §. But although the openness of the Aer permitting, be always 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 this; as in _Herbs_ 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 voided. 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.

24. §. 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 parts, 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; although now it would be no heavier, and in that respect, as apt for motion; yet would it have far less strength, than as its Parts are dilated to a _Circumferential_ posture. And so for _Quills_, which, for the same Reasons, in subserviency to flying, as they are exceeding light; So, in comparison with the thinness of their _Sides_, they are very strong, and much less apt to bend, than if contracted into a Solid _Cylinder_. 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, the same proportion as its heigth bears, to the thinness of its sides, doth the greatness of its Circumference also; being so far dilated as to parallel a _Quil_ it self.

25. §. Besides the position of the _Lignous Body_ within the compass of a _Ring_, there are 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.

26. §. Next, the security and plenty of the _Sap_. For should the _Lignous Body_, as it doth in the smaller Parts of the _Root_, 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 _Aer_; and being lodged 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 _Aer_ and _Sun_, but by the _Barque_, and especially the _Wood_, being also surrounded and doubly immur’d, will very securely and copiously be convey’d to all the Collateral Parts, and (as shall be said how) the top of the _Trunk_.

27. §. 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 _tun’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.

28. §. 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 _Herbs_, 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.

29. §. 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 _Herbs_, where the _Cortical Body_ is usually much and often wholly Inserted.

30. §. 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 _Herb_, by an accurate and steady view may be observed. But when I say the _Vessels_ 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_ or _Vessels_ of the 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 Aer 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 (considered as Aliment) it serveth only for the growth of the _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.

31. §. 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 and 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 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 _Herbs_ and _Trees_, with great _Piths_, the quickest and the longest? But how are the _Pores_ or _Bladders_ 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 _Aer_, 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 observe, that they are visibly more open by the breadth, than by the length. And withall 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 _Aer_. Whereas the _Pith_ in a Vegetating _Plant_, as its Parts or _Bladders_ are still generated, they are at the same time also fill’d with _Sap_; which, as ’tis gradually spent, is still repaired by more succeeding, and so the _Aer_ 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 _Bladder_, 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 _Bladders_ of the _Pith_ is discharged and repaired every moment, as by its shriv’ling up, upon cutting the _Plant_, is evident.

32. §. 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_ or _Bladders_ being 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_ or _Vessels_ 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 in very small Glasse Pipes, or betwixt the two halves of a Stick first slit, and then tyed somewhat loosely together, may also any Liquor be observed to do. By which Advantage the facility and strength of that ascent will be continued higher in the said _Vessels_, 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 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 _Vessels_ 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 replenished. 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 _Vessels_ 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 _Tree_.

_An Appendix._

_Of Trunk-Roots and Claspers._

THE distinct _Parts_ whereof these are composed, are the same with those of the _Trunk_, and but the continuation of them.

1. §. _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_.

2. §. 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 are a _Middle Thing_ betwixt a _Root_ and a _Trunk_.

3. §. _Claspers_, though they are but of one kind, yet their Nature is double; not a mean betwixit 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.

4. §. 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, though much more slender than the _Branches_ whereon they are appendent.

5. §. The _Claspers_ of _Bryony_ have a retrograde motion about every Third _Circle_, to the form a Doublet-Clasp. Probably for the more certain hold; which, if it miss one way, it may be sure to take another.

6. §. For Supply, we see the _Trunk-Roots_ of _Ivy_. For mounting very high, and being of a closer or more compact Substance 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 on one; that so they may be fastned at the nearest hand.

7. §. In the Trailing of the _Trunk_, they serve for stabiliment, propagation and shade. For stabiliment, the _Claspers_ of _Cucumbers_ are of good use. 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 Fruits, were they not by these Ligaments brought to good Association and Settlement.

8. §. As for this end, so for Propagation, the _Trunk-Roots_ of _Chamæmile_ do well serve. 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 is sometimes also effected in Rowling of _Corn_.

9. §. For both these ends, Serve the _Trunk-Roots_ of _Strawberries_; as also for shade; for in that 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.

CHAP. IV.

_Of the GERMEN, BRANCH, and LEAF._

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.

2. §. 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 from its _Inner_ or _Central Parts_; So as to take the _Pith_ in also. Divers of which _Parts_ 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 Succulent Part of the _Lignous Body_ of the _Trunk_ is sometimes principally from those Fibrous _Shoots_ which run along the _Pith_ in the _Root_.

3. §. 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 _Portions_ 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 _Portions_, 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_.

4. §. 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, they bind and throng each other into a _Knot_: through which _Knot_ the _Sap_ being strain’d, ’tis thus, in due moderation and purity delivered up into the _Branch_.

5. §. 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_.

6. §. 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 _older Branch_, and the _Basis_ of the Stalk of a _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 larger, and more hardy. The manner and uses of the position of every _Germen_, considered as after it becomes a _Branch_; hath already been, ♦ Hist. of the _Prop._ of _Veget._ ♦ by the Ingenious Mr. _Sharrock_ very well observed; to whom I refer.

7. §. 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, and 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 continuation of the _Cortical Body_, or _Parenchymous_ part of the _Barque_ from the _Branch_ into it self, as in most _Plants_ with a thick _Leaf_, may easily be seen.

8. §. The _Fibers_ of the _Leaf_ neither shoot out of the _Branch_, or the _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 _Chord_ of a Circle; as in _Cichory_, _Endive_, _Cabbage_, &c. may be observed. ♦ _Tab. 4. f. 2._ to _f. 11._ ♦ And if the _Leaf_ have but one main _Fiber_, that also is postur’d in a bowed or _Lunar_ Figure; as in _Mint_ and others. The usual number of these _Vascular Threds_ or _Fibres_ is 3, 5, or 7.

9. §. The reason of the said Positions of the _Fibers_ in the _Stalk_ of the _Leaf_, is for its more _Erect_ growth, and greater _Strength_: which, were the position of the said _Fibers_ 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_, ♦ _C. 3. §. 24._ ♦ we may better conceive.

10. §. As likewise for the security of its _Sap_: For by this means it is, that the several _Fibers_, and especially the main or middle _Fiber_ of the _Leaf_, together with a considerable part of the _Parenchyma_, are so disposed of, as to jut out, not from its upper, but its back, or nether Side. 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.