2. §. The Size of the Pith is various, being not the same in any two Branches here represented.Tab. 24, 31, 34, 35.
22, 29, 30, 32.
23, 25, 26, 35. 27.
28. In Wormwood, Sumach, Fig, Barbery, ’tis very large; sc. betwixt 5, and 7 Inches Diametre, as it appears through the Microscope. In Pine, Ash, Holly, Walnut, not so large; from 3 Inches Diameter to 4. In Oak, Apple, Pear, Hazel, lesser, scarce from 2, to 3. In Damascene, not above an Inch and half. And in Elm, scarce an Inch Diameter. Note also, that of all Plants, both Herbs, and Shrubs, have generally the largest Piths, in proportion with the other Parts of the same Branch, as in Sumach, Fig, Barbery, is manifest.

3. §. It is also worth the noting, That wheras, in most Plants, the Barque and Wood do both grow thicker every year: the Pith, on the contrary, groweth more slender; So that in a Branch of one years growth, it is apparently more ample, than in one of two; and in a Branch of two, than in one of three; and so on.

4. §. The Pith, for the most part, if not always, in the Branch, as well as the Root, is furnished with a certain number of Sap-Vessels. They are here usually so postur’d, as to make a Ring on the Margin of the Pith. Where they are more numerous, or large, they are more evident; as in Walnut, Fig, Pine, and others. They are also of divers Kinds, Tab. 30, 31, 32. answerable to those in the Barque; as in Wallnut, Lymphæducts; in Fig, Lacteals; in Pine, Resiniferous.

5. §. The Parenchyma of the Pith is composed of Bladders. Which are the very same with those in the Barque, and oftentimes in the Insertions within the Wood. Only these in the Pith, are of the largest Size; those in the Barque, of a lesser; and those of the Insertions least of all: for which reason they are less obvious than in the Pith.

6. §. The Bladders of the Pith, though always comparatively Great; yet are of very different Sizes. Being easily distinguished, even as to their Horizontal Area, to Twenty Degrees. Tab. 24, 31. Those of Fig, Barberry, and some others, are somewhat large. And of many Herbs, as of Thistle, Borage, and others, Tab. 39. three times as big again; appearing in the Microscope, like to the largest Cells of an Hony-comb. Those of Plum, Worm-wood, Sumach, less. Of Elm, Apple, Pear, lesser. Of Holly and Oak, still less. Tab. 32. So that the Bladders of the Pith in Borage or Common Thistle, are of that Size, as to contain, within the compass only of their Horizontal Area, about twenty Bladders of the Pith of Oak. Wherefore one whole Bladder in Thistle, is, at least an hundred times bigger, than another in Oak.

7. §. Of the Size of these Bladders of the Pith, ’tis also to be noted, That it doth not at all follow the Size of the Pith it self; but is still varied, according as Nature designeth the Pith for various use. Thus, whereas the Pith of Sumach, is Larger than that of Barberry; it might be thought, that the Bladders, whereof it is composed, should be likewise Larger: Yet are they Three times as Small again in Sumach, as they are in Barberry. Tab. 24, 34.
26, 27.
23, 33. So the Pith of Plum, is far Less than that of Pear; yet the Bladders of the former are Four or Five times as big, as those of the latter. So the Pith of Hazel is almost Three times as Little again, as that of Holly; yet the Bladders in Hazel, are Ten times bigger, than in Holly.

8. §. The Shape of the Bladders hath also some Variety. For although, for the most part, they are more round; yet oftentimes they are angular: as in Reed-grass, a Water-plant; where they are Cubical; and in Borage, Thistle, and many others, where they are pentangular, sexangular and septangular.

9. §. Of the Texture of the Bladders, ’tis also to be noted, that many times, the Sides of the greater Bladders are composed of lesser; as is often seen in those of Borage, Bulrush, and some other Plants. In the same manner, as the Sap-Vessels, are but greater Fibres made up of lesser.

10. §. The Pith, though always originally composed of Bladders, and so One Entire Piece; yet in process, as the Plant grows up, it hath divers openings or Ruptures made in it: oftentimes very regularly, and always for good use, and with constancy observed in the same Species of Plants. In Sharp-poynted Dock, many of the Pores are considerably prolonged by the length, like small Pipes. Tab. 19. In Walnut it shrinketh up into transverse Filmes or Membranes; as likewise sometimes in Spanish-Broom. Sometimes the Pith is hollow or Tubulary: either throughout the Trunk, as in Thistle, Endive, Scorzonera, Marsh-Mallow: or so, as to remain entire at every joynt; as in Sonchus, Nettle, Teasle; in which it is divided as it were into several Stories: and divers other ways.

11. §. I SHALL conclude this discourse with a further illustration of the Texture of the Pith, and of the whole Plant, as consequent thereupon. I say therefore, (and have given some account hereof in the Anatomy of Roots) That as the Vessels of a Plant, sc. the Aer-Vessels and the Lymphæducts are made up of Fibres; according to what I have in this Discourse above said; so the Pith of a Plant, or the Bladders whereof the Pith consists are likewise made up of Fibres. Which is true also of the Parenchyma of the Barque. And also of the Insertions in the Wood. Yea, and of the Fruit, and all other Parenchymous Parts of a Plant. I say, that the very Pulp of an Apple, Pear, Cucumber, Plum, or any other Fruit, is nothing else but a Ball of most extream small transparent Threds or Fibres, all wrapped and stitch’d up (though in divers manners) together. And even all those Parts of a Plant, which are neither formed into visible Tubes, nor into Bladders, are yet made up of Fibers. Which, though it be difficult to observe, in any of those Parts which are closer wrought and principally in the Insertions of some Trees: yet in the Pith, especially of some Plants, which consisteth of more open work, they are more visible. Which introduceth the observation of them in all other Parenchymous Parts. So in the Pith of a Bulrush of the Common Thistle, Tab. 38. and some other Plants; not only the Threds of which the Bladders; but also the single Fibres, of which the Threds are composed; may sometimes with the help of a good Glass, be distinctly seen. Yet one of these Fibres, may reasonably be computed to be a Thousand times smaller than an Horse-Hair.

12. §. The Fibrosity of the Parenchyma is also visible in some Woods, in which, it is apparently mixed with the Lignous Parts, not only by Insertions, but per minimas Partes organicas. That is to say, The Parenchymous Fibres, like smaller Threds, are either wraped round about both the Lignous and the Aer-Vessels, or at least interwoven with them, and with every Fiber of every Vessel: as in very white Ash or Fir-Wood, Tab. 39. with an advantagious posture and light, may be observed.

13. §. WHENCE it follows, that the whole Substance, or all the Parts of a Plant, so far as Organical, they also consist of Fibres. Of all which Fibres those of the Lymphæducts, run only by the Length of the Plant: those of the Pith, Insertions, and Parenchyma of the Barque, run by the breadth or horizontally: those of the Aer-Vessels, fetch their Circuit by the Breadth, and continue it by the Length.

14. §. By which means, the said Parenchymous Fibres, in fetching their horizontal Circles, do thus weave, and make up the Bladders of the Pith, in Open-Work. And the same Fibres being thence continued; they also weave and make up the Insertions, but in Close-Work. Betwixt which Insertions, the Vessels being likewise transversly interjected, some of the same Fibres wrap themselves also about these; thus tying many of them together, and so making those several Conjugations and Braces of the Vessels, which I have formerly described. And as some of these Horizontal Fibres are wraped about the Vessels; so also about the Fibres, whereof the Vessels are composed. By which means it is, that all the Fibres of the Vessels are Tacked or Stitched up close together into One Coherent Piece. Tab. 40. Much after the same manner, as the Perpendicular Splinters or Twigs of a Basket, are, by those that run in and out Horizontally. And the same Horizontal Fibres, being still further produced into the Barque; they there compose the same work over again (only not so open) as in the Pith.

15. §. SO THAT the most unfeigned and proper resemblance we can at present, make of the whole Body of a Plant, is, To a piece of fine Bone-Lace, when the Women are working it upon the Cushion, For the Pith, Insertions, and Parenchyma of the Barque, are all extream Fine and Perfect Lace-Work: the Fibres of the Pith running Horizontally, as do the Threds in a Piece of Lace; and bounding the several Bladders of the Pith and Barque, as the Threds do the several Holes of the Lace; and making up the Insertions without Bladders, or with very small ones, as the same Threds likewise do the close Parts of the Lace, which they call the Cloth-Work. And lastly, both the Lignous and Aer-Vessels, stand all Perpendicular, and so cross to the Horizontal Fibres of all the said Parenchymous Parts; even as in a Piece of Lace upon the Cushion, the Pins do to the Threds. The Pins being also conceived to be Tubular, and prolonged to any length; and the same Lace-Work to be wrought many Thousands of times over and over again, to any thickness or hight, according to the hight of any Plant. And this is the true Texture of a Plant: and the general composure, not only of a Branch, but of all other Parts from the Seed to the Seed.