The anatomy of plants with an idea of a philosophical history of plants, and several other lectures, read before the royal society / by Nehemjah Grew ...

CHAP. IV. Of the Wood.

THAT Portion of the Root which standeth next within the Barque, and in Trees, and Shrubby Plants, is the Wood; is also compounded of Two Substantially different Bodies, Parenchy∣mous and Lignous. The Parenchymous, is of the same Substantial Nature with that of the Barque. And is originated from it; being not only adjacent to it, but all round about conti∣nuous therewith; even as that, is with the Skin; the Parenchyma of the Barque, being distributed, from time to time, partly outward into the Skin, and partly inward, into the Wood.

2. §. The Position of the several parts hereof, is different. For the most part it hath a Diametral Continuation, in several Portions, run∣ning betwixt as many more of the Lignous, from the Circumference towards the Center of the Root: all together, constituting that, which in the Second Chapter of the First Book, I call the Insertment. In the Roots of many Herbs, these Diametral or Inserted Portions are more observable, as in Cumfry; which leadeth to the notice of them in all others,* 1.1 both of Herbs and Trees. Sometimes part of this Paren∣chymous Body is disposed into Rings, as in Fenil. The Number and Size of which Rings differ: In Fenil, when the Root is grown large, they are in some places broader,* 1.2 but fewer; in Beet they are narrower, but more. The Diametral Portions are here, in like manner, much va∣ried; in Cumfry, Celandine, larger; in Beet, Bugloss, meaner; in Bo∣rage, Parsnep, more, and smaller; and in most Woody-Roots, stream∣ing betwixt the Pith and the Barque, as so many small Rays. Their Continuation is also different; in some Roots, to the Centre, as in Co∣lumbine; in others not, as in Parsnep. And sometimes different in the same Root,* 1.3 as in the Vine.

3. §. The Contexture of these Parenchymous Portions is sometimes Uniform, as in Bugloss, Peony; and sometimes also, as it is in the Barque, different; in part, more sappy, and transparent; in part, more white, dry, and aery, as in Carrot, Lovage, Scorzonera, and others; which yet cannot be observed without a wary view. But their general Texture is the same being all made up of many small Blad∣ders. Which are here of different Sizes, like those of the Barque, but for the most part smaller. Their Shape likewise, is usually Round; but sometimes Oblong and Oval, as in Borage; or Oblong and Square, as in the Vine.* 1.4

4. §. The Lignous Part, if not always, yet usually, is also Com∣pounded of Two Kinds of Bodies, scil. Succiferous or Lignous and Aer-Vessels. The Lignous as far as discernable, are of the same Confor∣mation and Nature with those of the Barque, and in the transverse cut

of the Root, do oftentimes, as those, emit a Liquour. They are also Braced; and many of them run in distinct Threds or Portions, collate∣rally together.

5. §. The Aer Vessels I so call, because they contain no Liquor, bnt an Aery Vapour. They are, more or less, visible in all Roots. They may be distinguished, to the bare Eye, from the Parenchymous Parts, by their Whiter Surface; and their standing more prominent, wheras those shrink below the transverse level of the Root, upon drying. They are frequently Conjugated divers of them together,* 1.5 sometimes fewer, and for the most part single, as in Asparagus; sometimes many, as in Hors-Radish. And their Conjugations are also Braced, as the Threds of the Succiferous Vessels. But they are no where Inosculated: nor Twisted one about another; but only Tangent or Collateral. Neither are they Ramified, the greater into less; but are all distinctly continued, as the Nerves in Animals, from one end of the Root to the other.

6. §. Their Braces, as those of the Succiferous Vessels, are also of various number: in Jerusalem Artichoke, Cumfry, Scorzonera, more rare; in Borage, Burnet, more frequent; as by stripping off the Barque of such Roots,* 1.6 where it is easily separable, may be seen. And they often vary in the same Root; so in Borage, Scorzonera, &c. they are more frequent in the Centre, and next the Barque, than in the Intermediate space,* 1.7 as by splitting those Roots down the middle doth appear. They also vary from those of the Succiferous Vessels; those being usually more frequent, as in Jerusalem Artichoke, than these of the Aerial.

7. §. Betwixt these Braced Aer-Vessels, and the rest, which make the true Wood,* 1.8 run the Parenchymous Parts above described; as they do betwixt the Succiferous in the Barque: and so make up two Pieces of Net Work, wherof one is the filling up of the other.

8. §. The Position of both these Kinds of Vessels, is Various. The Succiferous or Lignous,* 1.9 are sometimes posited in diametral lines or porti∣ons; as in the Vine, and most Trees. Sometimes, oppositely to the Aerial,* 1.10 as in Beet; each Ring herein being double, and made both of Sap-and Aer-Vessels.

9. §. In Nettle the Position is very peculiar,* 1.11 from what it is in the Roots of other Herbs; being curiously mixed; the Succiferous running cross the Aerial, in several, viz. Five, Six, Seven, or more Rings. In Bryony the several Conjugations of the Aerial, are distinctly sur∣rounded with the Succiferous.* 1.12 In Patience, the Succiferous are disposed, besides Rays, into many small Rings, of different Sizes, sprinkled up and down, and not, as in other Roots having one common Centre; within divers whereof, the Aer-Vessels are included: especially within those which are drawn, not into Rings, but, as it were, into little stragling Hedges.

10. §. That also of the Aer-Vessels, is Various and Elegant: espe∣cially in the upper part of the Root. In Ammi, Lilium-non-bulbosom, they make a Ring. In these, a Prick'd-Ring; in Peony, a Ring of Rays;* 1.13 in Valerian, a Ring of Pricks and Rays. In others, they make not Rings, but longer Rays, extended either towards the Centre, as in Scorzenera; or meeting in it, as in Columbine. In the Common Dock, they stand more in single Rays: in the other Species of Docks, both in Rays, and collateral Conjugations between.

11. §. In Beet, they stand in several Rings; and every Ring, made of Rays. In Cumfry, the Rays and Rings are separate; those stand without,* 1.14 these next the Centre. In Dandelion, they stand alto∣gether, and make a little Rope, in the Center it self. In Geranium, and others of that Kindred, they make a little Thred, in the same place. And in Skirret, they stand in two Threds, near the Centre.

12. §. In Celandine, they stand in almost parallel Lines. In Monks-hood,* 1.15 of a wedged Figure; divided in the smaller part of the Root, into Three little Wedges, with their poynts meeting exactly in the Centre. In Cinquefoyle, and Strawberry, they are also postur'd in three Conjugations, triangularly. In the young Roots of Oak, they stand neither in Radiated, nor otherwise strait, but Winding Lines. And in Borage the position, of many of them, is Spiral. As likewise, sometimes, in Mercury, or Lapathum unctuosum. In Horse-Radish,* 1.16 they stand more confused neither in Rings nor in Rays; yet their several Conjugations, are radiated: with very many other dif∣ferences.

13. §. The Quantity of these Vessels, as to the space they take up in the Root, is to be computed Two ways, By their Number, and Size. Their Number may, in some Roots, and in some measure, be judged of, by the bare Eye; having, frequently, a whiter surface than the other Parts. As also their Size; the Bore of these Vessels be∣ing greater than that of the Lignous in all Roots; especially in some. For if you take the Roots of Vine, Fenil, Dandelion, Plum-tree, El∣der, Willow, &c. and lay them by, for some time, to dry; and then, having cut off a very thin Slice of each, transversely; if you hold up those Slices before your Eye, so as the Light may be trajected through the said Vessels, they hereby become visible, as notably different, both in Number and Size.

14. §. But undeceitful and accurate Observation of both their Number, and Size, must be made by the Microscope; and so they will appear to be much more various. In Bistort, Skirret, they are very few; in Beet, very many: betwixt which extreams there are all De∣grees; as in Orpine, Venus Looking-Glass, Scorzonera, Great Celandine, Peony, Borag••, Fenil, &c. may be seen. So their Size, in some is ex∣tream small, as in Strawberry, Bistort, Valerian; in others very great, as in Asparagus, Bugloss, Vine. They are also of several Sizes in one and the same Numerical Root; but in some, are less varied, as in Li∣lium 〈◊〉〈◊〉 bulbosum, Asparagus, Bugloss; in others, more, as in Bryony, Lovage.* 1.17 Amongst all Roots, they vary by about Twenty Degrees; as by comparing the Roots of Vine, Thorn-Apple, Bryony, Lovage, Fenil, Wild Carrot, Saxifrage, Parsley, Peony, Hore-hound, Cinquefoyl, Strawberry, &c. together, may be seen. Some of those in the Vine, being of the greatest Size; appearing through a good Glass, at least one Third of an Inch in Diametre: those in Strawberry, and that Kind, of the smallest; most of them appearing, in the same Glass, no bigger, than to admit the poynt of a small Pin, according to the Standard, in Tab. 12. See also the Figures of so many of them as are drawn.

15. §. In some Roots, they are Small, and Few; as in Jerusalem Artichoke;* 1.18 in others Small, but Many, as in Horse-Radish: in Bugloss, they are Great, but Few; in the Vine, Great and Many. So that the proportion, which those of a Vine, their Number and Size being taken together, bear to those of Jerusalem Artichoke, may be, at least, as Fifty, to One. Of the smallest Kinds, as those of Cinquefoyl, Jerusalem Arti∣choke, and the like; It is to be noted, That they are scarce ever visible in the fresh Slices of these Roots; but after they have layn by a while, at last, by a good Glass, Clear Light, and steddy View, are discerna∣ble.

16. §. In some Roots,* 1.19 the greater of these Vessels stand in or next the Centre, as in Taraxacum, or Dandelion; in others next the circum∣ference, as in Horse-Radish. Sometimes each of them is from one end of the Root to the other, of a more equal Size, or more Cylindrical, as in Marsh-mallow; but usually, they widen, more or less, from the Top, to the Bottom of the Root, as in Thorn-Apple: about the Top of which, they are, for the most part, but of the Sixth, Seventh, and Eighth, Magnitude; some of the Fifth, but none of the Third; but about the Bottome, they are most of the Third, and Fifth: whence it is manifest, That some of them are, in the manner of Veins, somewhat Pyramidal. Yet is it observable, That their ampliation proceedeth not towards, but from their Original, as in Nerves.

17. §. Of these Vessels Seignior Malpighi hath observed; Compo∣nuntur (saith he) expositae fistulae Zona tenui & pellucida, velut argentei coloris lamina, parum lata; quae, spiraliter locata, & extremis lateribus unita, Tubum, interius & exterius aliquantulum asperum, efficit.

18. §. To whose Observation I further add, That the Spiral Zone, or Lamina, as he calls it, is not ever one Single Piece; but consisteth of Two or More round and true Fibres, although standing collaterally together, yet perfectly distinct. Neither are these Single Fibres themselves flat, like a Zone; but of a round forme, like a most ••ine Thred. According as fewer or more of these Fibres happen to break off, from their Spiral location, together; the Zone is narrower, or broad∣er: usually, Narrower in the Trunk, and Broader in the Root.

19. §. Of these Fibres I also Observe, That they are not Inosculated side to side, but are Knit together by other smaller Fibres; those be∣ing, as it were, the Warp, and these the Woof of the Aer-Vessels. Yet I think the several Fibres are not interwoven just as in a Web; but by a kind of Stitch, as the several Plates or Bredths of a Floor-Mat. A clear and elegant sight of these Fibres, and of their Interwestage, by splitting a Vine-Root, or a piece of Oak, may, with a good Glass in the sides of their Greater Aer-Vessels, be obtained; having much of the re∣semblance of Close Needle-work.

20. §. The Spiration of the Fibres of these Vessels, may more easily be observed in the Trunk, than in the Root. And better in younger Plants, than other. And not so well by Cutting as by Splitting, or by Tearing off some small Piece, through which they run: their Conforma∣tion being, by this means, not spoiled. Yet this way, the Vessels are seen, chiefly, Unresolved.

21. §. But in the Leaves and Tender Stalks of all such Plants, as shew, upon breaking, a kind of Doune or Wool; they may be seen Resolved and Drawn out, and that some times even to the naked Eye,

an Inch or two Inches in length. This Wool being nothing else, but a certain number of Fibres Resolved from their Spiral position in these Vessels, and Drawn out in Length; and so clustred together, as so many Threds or little Ropes: appearing thus more or less, in the Leaves and some other Parts of most Plants; but more remarquably in some, as in the Vine, Scabious, and others. As also in the Scales of a Squill. In which last, for example, they are so easily separable, as further to shew, what before was observed; viz. That the Plate or Zone, into which the Aer-Vessels are usually Resolved, is not one Single Piece, or meer Plate; but made up of several Round Fibres, all standing and running parallel, and so knit together by other smaller ones, trans∣versly, in the form of a Zone. For if you break or cut a Leaf or Shell of a fresh Squill, till you come to the Aer-Vessels, and having softly drawn them out, for about an Inch or more (to the naked Eye) in length, you then single out one or two of them from the rest, and rowl them, as they hang at the Shell, eight or nine times round, each Vessel will appear, through a Glass, to consist of 8, 10, or 12 small Fibres; which, in the Unresolved Vessel, run parallel; but by this means, are all separated one from another. See the Figures belonging to the Third and Fourth Books.

22. §. The Process of their Spiration, is not, so far as I have ob∣served, accidental, but constantly the same; scil. In the Root, by South, from West to East: But in the Trunk, contrarily, by South, from East to West.

23. §. The Content of these Vessels, is, as hath already been inti∣mated, more Aery. The Arguments for which, are, That upon a transverse Cut of the Root, the Sap ascendeth not there, where These stand. Being also viewed through a Microscope, they are never observed to be filled with Liquor. Besides a Root cut and immersed in Water, till the Water is in some part got into these Vessels, and then the Root taken out and crushed; the other Parts will yield Liquor, but These, only Bubbles: which Bubbles are made, by some small quantity of Liquor mixed with the Aer, before contained in the said Vessels. To which, other Arguments will arise out of those Things that follow in the Second Part. As also for this Content, its not be∣ing a pure or simple, but Vaporous Aer. Whether these Vessels may not, in some Vegetables, and at some times, contain Liquor, is doubt∣ful. a 1.20 Thus far of the Lignous Part.

Notes

• * 1.1

  Tab. 9.
• * 1.2

  Tab. 8, 9.
• * 1.3

  Tab. 17.
• * 1.4

  Tab. 17.
• * 1.5

  Tab. 10, & 15.
• * 1.6

  Tab. 6.
• * 1.7

  Tab. 6.
• * 1.8

  Tab. 6.
• * 1.9

  Tab. 17.
• * 1.10

  Tab. 8.
• * 1.11

  Tab. 8.
• * 1.12

  Tab. 7.
• * 1.13

  Tab. 7, 8, 9.
• * 1.14

  Tab. 8, 9.
• * 1.15

  Tab. 8, 9.
• * 1.16

  Tab. 15.
• * 1.17

  Tab. 10. to the 17.
• * 1.18

  Tab. 11, 14, 15, 17.
• * 1.19

  Tab. 13, 15.
• a 1.20

  See Book 3.