PART I.

CHAP. I.

_The Descriptions of several_ Trunks, _as they appear to the bare Eye._

_TO the_ end we may clearly understand, what the _Trunk_, _Stalk_, or _Branch_ of a _Plant_, is; I shall by these _Figures_ here before us, Describe the several _Parts_, whereof it is compounded.

1. §. And for examples sake, I shall in the first place, Describe the _Trunks_ of some _Plants_, as being cut tranversly, and accurately observ’d, they appear to the naked Eye. And some others, as by the length. Which having done, I shall next proceed to a more particular Description of divers other _Trunks_ and _Branches_ as they appear through a good _Microscope_. In both shewing, not only what their several _Parts_ are, as generally belonging to a _Branch_; but also, by a Comparative Prospect, in what respects they are _specifically_ distinguished one from another, in the several _Sorts_ of _Branches_.

2. §. I SHALL begin where the Work of _Nature_ appears less Diversify’d: as in the _Stalk_ of _Maze_ or _Indian Wheat_. In which, although there are the same _Parenchymous_ and _Lignous Parts_, as in all other _Plants_; ♦ _Tab. 18._ ♦ yet is there neither _Barque_, nor _Pith_; the _Vessels_ being dispersed and mixed with the _Parenchyma_, from the Circumference to the Centre of the _Stalk_: Saving, that in and next the _Skin_, there seems to be no _Aer-Vessels_. Every where else, they run up, like fine _Threds_, through the length of the _Stalk_: Each _Thred_ being also surrounded with _Sap-Vessels_; which in a Slice cut transversly, appear in very small and dark colour’d _Rings_. The like structure may also be seen in the _Sugar-Cane_, and some other _Plants_.

3. §. LET the next _Trunk_ be that of _Taraxacum_, or _Dandelion_. In a _slice_ whereof, being cut transversly, is seen next the _Skin_, first, a simple, white, and close _Parenchyma_ or _Barque_; ♦ _Tab. 18._ ♦ made up of _Vesicles_; but such as are exceeding small; and hardly visible without a _Glass_.

4. §. Within This, stand _Milk-Vessels_ in seven or eight distinct _Colums_, of different size: each _Colum_ being also made up of seven or eight _Arched Lines_. Betwixt these _Colums_, run as many _Diametral Portions_, derived from the _Barque_, into or towards the _Pith_.

5. §. Next within These, stand the _Aer-Vessels_. Which are likewise divided, by the said _Diametral Portions_, into divers _Arched Lines_. The _size_ of these _Vessels_, as well as their _number_, is small.

6. §. Within These, stands the _Pith_, consisting of very small _Vesicles_ or _Bladders_, as the _Barque_. ’Tis very small, the _Diameter_ hereof, being scarce one _fifth_, of that of the _Pith_ of _Borage_. But the _Barque_ of _Borage_ is not half so thick as this of _Dandelion_.

7. §. FOR a Third _Stalk_, we may take that of _Borage_; wherein there is some further Variety. For in a _slice_ hereof, cut transversly, there appears, first a Tough, yet Thin and Transparent _Skin_. Within this _Skin_, and _Continuous_ therewith, there is also a Thin _Ring_ of _Sap-Vessels_: ♦ _Tab. 18._ ♦ which, without being crushed in the least, do yield a _Lympha_.

8. §. Next standeth the _Parenchyma_ of the _Barque_. Which is made up of a great number of very small _Vesicles_ or _Bladders_. Upon the inner _Verge_ of this _Parenchyma_, standeth another _Ring_ of _Sap-Vessels_: which also yield a _Lympha_; and that different, as is probable, from the _Lympha_ in the utmost _Ring_. Hitherto goes the _Barque_.

9. §. Adjacent to the _Ring_ of _Sap-Vessels_, on the inner _Verge_ of _Barque_, stand the _Aer-Vessels_ on the outer _Verge_ of the _Pith_. Not in a _Ring_; but in several _Parcels_; some _Parcels_ or _Conjugations_, in the figure of little _Specks_; others, in little _Arched Lines_, almost like an V _Consonant_. And being viewed in a good _Glass_, there appears to be within the compass of every larger _Speck or Parcel_, about 20 or 30 _Aer-Vessels_ and within the smallest, about 8 or 10.

10. §. The _Pith_, in a well grown _Stalk_ of this _Plant_; is always _hollow_. But originally, it is _entire_. It is likewise wholly made up of a great number of _Vesicles_: of which, through a _Glass_, some appear _Pentangular_, others _Sexangular_, and _Septangular_. Most of them are larger than those of the _Barque_; so as to be plainly visible to a naked Eye.

11. §. A FOURTH _Trunk_, shall be that of _Colewort_, which seems likewise, to have at least, two Sorts of _Lymphæducts_. For being cut transversly, as the former, we may observe, next the _Skin_, a very close _Parenchyma_, of a darkish Green. Wherewith are mixed some few _Sap Vessels_, which give it that _Colour_.

12. §. Within This, stands a _scalloped Parenchymous Ring_, or a _Ring_ of many short and slender white _Arches_. ♦ _Tab. 18._ ♦ Which all round about the _Barque_, meeting together, run in so many white _Diametral Portions_, or extream small _Rays_, into the _Pith_.

13. §. Betwixt these white _Rays_, and next of all to the said white _Arches_, stand as many small _Parcels_ of _Sap-Vessels_, like so many little _Half-Ovals_. Within each of which, is included a white _Parenchyma_.

14. §. On the inner _Verge_ of the _Barque_, stands another Sort of _Sap-Vessels_, in one slender and entire _Ring_. And so far goes the _Barque_.

15. §. Next within this _Ring_ stand the _Aer-Vessels_, in several _Parcels_, diametrically opposite to the said white _Parenchymous Parcels_ next without the _Sap-Ring_.

16. §. Last of all, and more within the _Pith_, stand the same kind of _Sap-Vessels_, as those of the _Half-Ovals_. Both these, by small lines, run one into another; thus, on both sides, hemming in the _Aer-Vessels_, and so making altogether, so many little _Pyramids_.

17. §. LET a _Fifth_ be that of _Holyoak_. In which, the Curiosity of _Nature_, is still more copious: presenting us, as it seems, with Three sorts of _Lymphæducts_; Of which, two yield a _Thin_; the Third, a _Thick Lympha_. For being cut, as before, next to the _Skin_, stands the _Barque_; somewhat close, and, in proportion, _Thick_.

18. §. Towards the inner _Verge_ hereof, stand one sort of _Sap-Vessels_, postur’d in short _Rays_. These _Vessels_ yield a _Mucilage_. And on the inner _Verge_ of the _Barque_, stands a Thin _Ring_ of other _Sap-Vessels_, which yield a _thinner Liquor_. ♦ _Tab. 18._ ♦

19. §. Next within the _Barque_ stand the _Aer-Vessels_, postur’d likewise in short _Rays_, diametrically opposite to those in the _Barque_. In every _Ray_, there are about twelve or sixteen _Vessels_.

20. §. Lastly, and more within the _Pith_, there stand other _Sap-Vessels_, all in very Thin or Slender _Arched-Lines_; thus hemming in the several _Parcels_ of _Aer-Vessels_.

21. §. FOR a _Sixth_, I will take that of Wild _Cucumer_: Wherein is also found a _Mucilaginous Lympha_. For first of all, next to the _Skin_, there is a _Ring_ of _Sap-Vessels._ Which _Ring_ is also radiated, the _Rays_, all poynting towards, and most of them terminating on, the _Skin_. ♦ _Tab. 18._ ♦

22. §. Next of all, there is a thick, and simple _Parenchymous Ring_. On the inner _Verge_ whereof, there are other _Sap-Vessels_ standing in _Parcels_, also in a _Ring_. So far goes the _Barque_.

23. §. Next within, stand the _Aer-Vessels_, in as many _Parcels_, contiguous to those of the _Sap-Vessels_ aforesaid. To which likewise are adjoyned as many more _Parcels_ of _Sap-Vessels_ within the _Pith_, opposite to the said _Sap-Vessels_ within the _Barque_.

24. §. FOR a _Seventh_, we may choose that of _Scorzonera_. In which, the _Vessels_ are both _Lymphæducts_, and _Lactiferous_. All of them, with the _Aer-Vessels_, in a radiated posture. For first next the outer Edg of the _Barque_, stand the _Lactiferous_, in little _Specks_. ♦ _Tab. 18._ ♦ Next to these, on the inner Edg of the _Barque_, stand the _Lymphæducts_, in the same form.

25. §. Hereunto adjacent, on the outer Edg of the _Pith_, stand the _Aer-Vessels_, some in _Specks_, and some in extream short _Lines_; hardly distinguished, without a very nice Inspection.

26. §. Within These, are placed other _Lymphæducts_, opposite to those in the _Barque_. And within these _Lymphæducts_, still in the same radiated Line, run more of the _Milk-Vessels_.

27. §. AN EIGHTH, may be that of _Burdock_; Wherein first, there are a Sort of _Lymphæducts_, which stand in _Arched Parcels_, round the _Trunk_, adjacent to the _Skin_. ♦ _Tab. 18._ ♦

28. §. Within these, about the middle of the _Barque_, run the _Milk-Vessels_, in the form of small round _Specks_.

29. §. Next to these on the inner Edg of the _Barque_ are placed other _Lymphæducts_. Which, together with more of the same in the _Pith_, and the _Aer-Vessels_ betwixt them, stand all in Radiated Lines, of several Lengths, and all sharpning towards the Centre.

30. §. LET the _Ninth_, be that of _Endive_: In which there is also much curious Work. ♦ _Tab. 18._ ♦ Next to the _Skin_, there is, first, a thick and simple _Parenchyma_. Then there is a kind of _Undulated Ring_ of _Milk-Vessels_. Within which stand a Sort of _Lymphæducts_, in several _Parcels_; some, in _Arched Half-Ovals_; others, in short slender _Rays_. Betwixt these _Parcels_, many of the _Milk-Vessels_ likewise stand.

31. §. Next there is an _undulated Ring_ of other _Lymphæducts_, parting as in most _Trunks_, betwixt the _Barque_ and the _Pith_. Within which, are the _Aer-Vessels_. And within These, more _Sap-Vessels_. Both of them, in small _Specks_, answerable, or opposite to the _Rays_ in the _Barque_.

♦ _Tab. 18._ ♦ 32. §. I SHALL give also one or two Examples of _Trees_, or _Arborescent Plants_; the _Vine_ and _Common Sumach_. In a Slice of the former cut transversly, next the _Skin_, there is a Thin _Barque_. In the inner part whereof, adjacent to the _Wood_, stand the _Lymphæducts_ in several _Half-Oval Parcels_, opposite to so many Radiated Pieces of the _Wood_.

33. §. The _Wood_ is divided into the said Pieces, by as many _Parenchymous Rays_, inserted from the _Barque_, and so continuous therewith.

34. §. Within these Radiated Pieces of _Wood_, stand the _Aer-Vessels_; the largest of which, especially if held up against the light, are plainly visible to the bare Eye.

35. §. Within the hollow of the _Wood_, stands the _Pith_; in the young Growths always large. In the utmost _Verge_ whereof, adjacent to the _Wood_, stand a few more _Sap-Vessels_ of the same Sort with those in the _Barque_.

♦ _Tab. 18._ ♦ 36. §. IN A like Slice of _Common Sumach_, contiguous to the hairy _Skin_, there is a _Ring_ of _Lymphæducts_. Next to this a Simple _Parenchyma_. Then several _Arched Parcels_ of _Lymphæducts_. Within these, a _Ring_ of _Milk-Vessels_. And then a _Ring_ of other _Lymphæducts_. Thus far the _Barque_.

37. §. Within the _Barque_, stands the _Wood_, divided into several _Portions_, by the Diametral _Insertions_ divided from the _Barque_. In the Body of the _Wood_, stand the _Aer-Vessels_, very much smaller than in the _Vine_.

38. §. The hollow of the _Wood_ is filled up with the _Pith_. In the Circumference of which, stands a _Ring_ of _Lymphæducts_, of the same sort with those next to the _Wood_ without.

39. §. All the _Parts_ of these _Trunks_, may, as I have now described them, be observed without a _Microscope_: excepting the _Bladders_ and number of _Aer-Vessels_. Yet Three things are hereunto necessary; _viz._ a good _Eye_, a clear _Light_, and a _Rasor_, or very keen _Knife_, wherewith to cut them with a smooth surface, and so as not to Dislocate the _Parts_.

40. §. UPON _Inspection_ also by the length, there are some particulars, common, more or less, to most _Plants_, yet better observable in some, than in others. As first, the _Reticulation_ of the _Vessels_, (formerly described) not only in the _Wood_, but in the _Barque_: ♦ _Tab. 19._ ♦ which is evident in a young _Branch_ of _Corin_, upon the very Surface thereof, when some of the _Vessels_ begin to be cast off into the _Skin_. And so, by stripping off the _Skin_, upon the Surface of the _Wood_.

41. §. In cutting by the length, as well as transversly, the young _Fibres_, which grow within the _Wood_ in the Edg of the _Pith_, are also seen. As likewise the manner of the Derivation of the _Parts_ of the _Bud_ from the _Branch_ or _Stalk_; as in _Sonchus_. There are also many Varieties in the _Pith_, such as those hereafter mentioned[57] which fall under observation only in cutting by the length.

[57] _Chap. 4._

CHAP. II.

_Of the_ Barque, _as it appears through a good Microscope._

I NOW proceed to a more particular _Description_ of several _Trunks_ and _Branches_, as they appear through good _Glasses_.

1. §. Now the _Trunk_, or _Branch_ of every _Tree_, hath Three General _Parts_ to be described; _sc._ the _Barque_, the _Wood_, and the _Pith_. That likewise of every _Herbaceous Plant_, hath either the same Three _Parts_; or else Three _Parts_ Analogous; _sc._ the _Cortical_, the _Lignous_, and the _Pithy Parts_.

2. §. The _Barque_ consisteth of two _Parts_, _sc._ the outmost or _Skin_, and the _Main Body_. The _Skin_ is generally composed, in part, of very small _Vesicles_ or _Bladders_, cluster’d together. That is, originally it is so; but as the _Plant_ grows, the _Skin_ dries, and the said _Bladders_, do very much shrink up and disappear.

3. §. Amongst these _Bladders_ of the _Skin_, there are usually intermixed a sort of _Lignous Fibres_, or _Vessels_, ♦ _Tab. 20._ ♦ which run through the length of the _skin_; as in _Mallow_, _Nettle_, _Borage_, _Thistle_, and most _Herbs_. Which is argued not only from the Toughness of the _skin_ by means of the said _Vessels_; but in some _Plants_, may be plainly seen, as in _Teasle_. In which, the several _Fibres_, which run by the length of the _Stalk_, are also conjoyned by other smaller ones, which stand transversly.

4. §. Whether they are _Aer-Vessels_, or _Sap-Vessels_, is dubious. For, on the one hand, because they emit no _Sap_, or _bleed_ not, and also stand adjacent to the _Aer_; ’tis probable that they are _Aer-Vessels_. On the other hand, they may be _Sap-Vessels_; notwithstanding that they _bleed_ not: Because the non-emission of _Sap_ is not an infallible and concluding argument of an _Aer-Vessel_. For there are some _Plants_ which _bleed_ not. Which yet are furnished with _Sap-Vessels_, as certainly as any others which _bleed_.[58]

[58] _B. 2. P. 1. c. 3. §. 22._

5. §. The _Skin_ of the _Trunk_ is sometimes visibly porous. But no where more, than in the better sort of walking _Canes_; where the _Pores_ are so big, as to be visible even to the naked Eye: like to those, ♦ _Tab. 20._ ♦ which are observable in several parts of the Ball of the _Hand_, and upon the ends of the _Fingers_ and _Toes_.

6. §. THE _Main Body_ of the _Barque_ consisteth likewise of two _Parts_, _sc._ _Parenchyma_, and _Vessels_. The _Parenchyma_ is made up of an innumerable company of small _Bladders_ cluster’d together. Differing in nothing from those aforesaid in the _Skin_; ♦ _Tab. 22. & Sequent._ ♦ saving, that they are much larger; and generally rounder.

7. §. This _Parenchyma_ of the _Barque_ is the same, as to its _Substance_, both in the _Root_ and _Trunk_. Yet as to the _Texture_ of its _Parts_, in the _one_, and in the _other_, there _is_ This observable difference, _viz._ That in the _Barque_ of the _Root_, cut transversly, the said _Parenchyma_ (as hath been shew’d) is usually, more or less, disposed into _Diametral Rays_; ♦ _Tab. 7, 8, 9._ ♦ running through the _Barque_, after the same manner, as do the _Hour-Lines_ through the Margin of the _Dial-plate_ of a _Clock_ or _Watch_: as in _Marsh-Mallow_, _Lovage_, _Melilot_, and others. Whereas here in the _Barque_ of the _Trunk_, the said _Parenchyma_ is rarely thus disposed into _Diametral Rays_: ♦ _Tab. 22. & Seq._ ♦ Nor when it is, are those _Rays_ continued to the Circumference of the _Barque_; as in the _Barque_ of the _Root_ they frequently are. ♦ _Tab. 31, 34, &c._ ♦ So in _Rhus_ or _Sumach_, although part of the _Parenchyma_ be dispos’d into _Diametral Rays_: yet are those _Rays_ extended not half way through the _Barque_. So also in _Fig-tree_, _Worm-wood_, _Thistle_, and others. What is further observable in the _Texture_ of the _Parenchyma_, I shall shew in the description of the _Pith_.

8. §. THE _Vessels_ of the _Barque_, are, as I shall also shew, diversifyed many ways. But there are some Things, wherein, in all Sorts of _Plants_, they agree. _First_, in standing, most numerously, in or near, the inner Margin of the _Barque_. _Secondly_, in being always, and only _Sap-Vessels_. I have viewed so many, that at least, I can securely affirm thus much, That if there be any Heteroclital _Plants_, wherein they are found otherwise, there is not _One_, in _Five Hundred_. _Thirdly_, in being always _Conjugated_ or _Braced_ together in the form of _Net-work_. Although the Number and Distances of the _Braces_, are very different: ♦ _Chap. 3. Tab. 6._ ♦ as I have already shewed in the _Anatomy_ of _Roots_.

9. §. THE Properties, whereby the said _Vessels_ of the _Barque_ are specificated and distinguished one from another, both in the same _Plant_, and in the several Species of _Plants_, are very many. Which Properties, are not Accidental, but such as shew the Constant and Universal Design of _Nature_. All which shall be demonstrated by the _Description_ of several _Quarters_ of the _Slices_, of so many Kinds of _Branches_, cut Transversly: and by the several _Figures_ which represent them.

10. §. FIRST then, for the _Eleven_ first _Quarters_, the _Vessels_ of the _Barque_ are only of _Two Kinds_. ♦ _Tab. 22. & Seq._ ♦ And these, in the first _Eight_, seem to be _Roriferous_ (described also in the _Anatomy_ of _Roots_)[59] and those which are common to most, if not to all _Plants_, sc. the _Lymphæducts_. Yet in all the _Eight_, they are, in respect both of their _Proportion_, and _Position_, very different. So in _Hazel_ and _Ash_ they are but few. In _Holly_ and _Barberry_ more. In _Apple_, _Pear_, _Plum_, _Elm_, still more numerous. And of those three _Fruits_, in an _Apple_, or _Plum_, more than in a _Pear_.

[59] _P. 1. c. 3. §. 22._

11. §. Again, as their _Proportion_, so likewise their _Position_ is divers. For in _Holly_, the _Lymphæducts_ or inner _Vessels_ next to the _Wood_, stand in _Rays_. Yet so numerous and close together, as to make one Entire _Ring_. ♦ _Tab. 22, 23, 24._ ♦ In _Hazel_, they stand more in Oblong _Parcels_. In _Barberry_, they stand likewise in _Parcels_, but they are so many _Half-Ovals_. The utmost _Vessels_ or _Roriferous_ of all Three, make a _Ring_.

12. §. Again, in _Apple_, _Pear_, and _Plum_, the _Lymphæducts_ are _Radiated_. The _Roriferous_ are neither _Radiated_, nor make an _entire Ring_; ♦ _Tab. 25, to 28._ ♦ but stand in _Peripherial Parcels_. Much after the same manner, they also stand in _Elm_. In _Ash_, the _Vessels_ make Two _Rings_; ♦ _Tab. 29._ ♦ but neither of them _Radiated_: the inmost _Ring_ or _Lymphæducts_, consisting of _Arched Parcels_, and the utmost or _Roriferous Vessels_, of _Round_ ones. And whereas in all the foregoing, the _Lymphæducts_ are still contiguous to the _Wood_; and the _Roriferous_ more or less, distant from the _Skin_: here, on the contrary, the former are distant from the _Wood_, and the latter contiguous to the _Skin_.

13. §. And that these _Vessels_ in each _Barque_ of the said Eight _Branches_, are of Two distinct Kinds, seems evident, as from some other reasons, so from hence; In that their _Positions_ are altogether Heterogeneous: Yet in both Constant, Regular and Uniform. I say, there seems to be no Reason, why the self _same Kind_ or Species of _Vessels_, should have a different, yea a contrary _Position_ in one and the same _Plant_; and that Contrariety, not _Accidental_, but _Regular_ and _Constant_.

14. §. FOR the _Three_ next _Quarters_ _sc._ the _Ninth_, _Tenth_ and _Eleventh_, the _Vessels_ of the _Barque_ are also different in _Number_, _Position_, _Size_ and _Kind_. ♦ _Tab. 30, 31, 32._ ♦ In _Pine_, which is the _Eleventh_, they are fewer. In _Walnut_, the _Ninth_, more. In _Fig_, the _Tenth_, most numerous.

15. §. So for their _Position_. In _Pine_, the inmost make a _Radiated Ring_. The utmost stand _stragling_ up and down, without any certain order. In _Wallnut_ the inmost make also a _Radiated Ring_; The utmost make a Double _Ring_; not _Radiated_, but of _Round Parcels_. In _Fig_, the inmost make also a _Radiated Ring_. But the utmost make a _Double_ and sometimes _Treble Ring_, not of _Radiated_, nor _Round_, but _Arched Parcels_.

16. §. Thirdly, they are also different in _Kind_. Those, I think, of the two former, _Wallnut_ and _Fig_, are thus different: those certainly, of the _Fig_, are so; being _Lymphæducts_ and _Lacteals_. The _Lymphæducts_ make the inmost _Radiated Ring_. The outmost which make the other _Rings_ in _Arched Parcels_, are the _Lactifers_.

17. §. That they are distinct _Kinds_ of _Vessels_, is evident for two Reasons. _First_, from their _Position_ in the _Barque_; which is altogether different, as hath been said. _Secondly_, from the most apparent Diversity of the _Liquors_ or _Saps_, which they contain, and which, upon cutting the _Branch_ transversly, do distinctly _Bleed_ from them. Which is one way, whereby we do distinguish the _Vessels_ of _Animals_ themselves. As in the _Liver_, it were hard to say, which is a _Blood-Vessel_, and which is a _Bile-Vessel_, where they are very small, if it were not for the _Contents_ of them both.

18. §. Those in the _Barque_ of _Pine_, are likewise of Two _Kinds_. The inmost are _Lymphæducts_, as in the two former. The utmost are not _Milk-Vessels_, but _Gum-Vessels_, or _Resiniferous_; which stand stragling, and singly, about the midle of the _Barque_. Out of these _Vessels_ all the clear _Turpentine_, that drops from the _Tree_, doth issue.

19. §. Few, but very great. So that besides the difference of their _Number_ and _Position_, and of the _Liquors_ which they contain, and _Bleed_; there is yet a Fourth, and that is, their _Size_. Most of these _Turpentine Vessels_, being of so wide a _bore_, as to be apparent to the naked Eye: and, through a good _Glass_, above ⅓ᵈ of an Inch in Diametre. Whereas that of the _Lymphæducts_, can hardly be discovered by the best _Microscope_.

20. §. The same _Turpentine-Vessels_ of _Pine_, are likewise remarkably bigger, not only than the _Lymphæducts_, but many times, than the _Milk-Vessels_ themselves: as those of the _Fig_, which, in comparison, are exceeding small; every _Arch_, not being a _single Vessel_, but a _Parcel_ or _Cluster_ of _Vessels_; Whereas one single _Gum-Vessel_ in _Pine_, is sometimes as big as two whole _Arched Clusters_, that is, as some Scores of the _Milk Vessels_ in a _Fig-tree_. And the said _Gum-Vessels_ of _Pine_, being compared with the _Lymphæducts_ of the same _Tree_, one _Gum-Vessel_, by a moderate estimate, may be reckoned _three_ or _four hundred_ times _wider_ than a _Lymphæduct_. The like prodigious difference may be observed in the _Size_ of the several _Kinds_ of _Vessels_ of many other _Plants_.

21. §. THE _Three_ next _Quarters_ of _Branches_, are of _Oak_, _Common Sumach_, and _Common Wormwood_. In the _Barque-Vessels_ whereof, there is observable some farther Variety. For in all or in most of the above named, there are only Two _Kinds_ of _Vessels_ in the _Barque_. But in Each of these, there are, at least, Three _Kinds_.

22. §. And first, in that of _Oak_ there are _Lymphæducts_, _Roriferous_, and a Sort of _Resiniferous_. ♦ _Tab. 33._ ♦ The inmost or _Lymphæducts_, make a _Radiated Ring_, contiguous to the _Wood_. The utmost or the _Roriferous_ make also a _Ring_, but not _Radiated_. Those which are a sort of _Rosin-Vessels_, stand in Round _Parcels_; the greater _Parcels_ betwixt the Two _Rings_ of _Roriferous_ and _Lymphæducts_; and the lesser, betwixt the _Roriferous_ and the _Skin_.

23. §. That these last are different _Vessels_ from both the other, seems evident, from the difference of their _Position_, as aforesaid. And that they are a sort of _Resiniferous_, is argued from hence; In that, not only _Galls_ are very full of _Rosin_, but that the _Barque_ of _Oak_ it self is also somewhat _Resinous_. For the conveyance of whose _Resinous_ parts, it is most unlikely that any other _Vessels_ should subserve, but a peculiar _Kind_; which may therefore be properly called _Resiniferous_.

♦ _Tab. 34._ ♦ 24. §. The next is a _Branch_ of _Common Sumach_. In the _Barque_ whereof, there are likewise Three _Kinds_ of _Vessels_. First of all, there is a thick _Radiated Ring_ of _Lymphæducts_; standing on the inner _Margin_ of the _Barque_, contiguous with the _Wood_. These _Vessels_ exhibit their _Lympha_ very apparently. A second kind of _Vessels_, _sc._ _Roriferous_, are situate towards the outer _Margin_ of the _Barque_, and are composed into distinct _Arched Parcels_, all standing in a _Ring_.

25. §. Betwixt these Two _Kinds_ stand the _Milk-Vessels_. Every single _Milk-Vessel_ being _empaled_ or hemmed in with an _Arch_ of _Roriferous_. The _Milk-Vessels_ are extraordinary large, almost as the _Gum-Vessels_ of _Pine_; so as distinctly to be observed without a _Microscope_; after they are evacuated of their _Milk_; and without difficulty will admit a _Virginal Wyer_; being two or three hundred times as big as a _Lymphæduct_. Besides these Three sorts of _Vessels_, there is also a _Ring_, adjacent to the _Skin_; which seems to be another sort of _Roriferous_.

26. §. The Last, is a _Branch_ of _Common Wormwood_. ♦ _Tab. 35._ ♦ In the _Barque_ whereof, there are likewise Three _Kinds_ of _Vessels_. First of all, there is a thin _Radiated Ring_ of _Lymphæducts_, contiguous with the _Wood_ or on the inner _Margin_ of the _Barque_. Yet the _Ring_ is not entire, but made up of several _Parcels_; which are intercepted by as many _Parenchymous_ inserted into the _Pith_.

27. §. A Second Sort of _Vessels_, which seem to be _Roriferous_, are situate about the middle of the _Barque_: and are composed into _Arched Parcels_, which likewise stand all even in a _Ring_.

28. §. Beyond these _Arches_, and towards the outer _Margin_ of the _Barque_, stand a Third Sort of _Vessels_. Different from the _Milk-Vessels_ in _Sumach_, both as to their _Situation_, _Size_ and _Content_. For in _Sumach_, the _Milk-Vessels_ stand within the _Arched Lymphæducts_: whereas these in _Wormwood_, stand without them. Likewise, being the _Vessels_ of an _Herb_, they are far less; _sc._ about the compass or width of a small _Wheat-Straw_. Their _Content_, is not a _Milk_, but a _liquid_, most _Oleous_ and _viscid Gum_. Or which, for its pleasant _Flavour_ may be called an _Aromatick Balsom_. For it perfectly giveth whatever is in the _Smell_ and _Taste_ of _Wormwood_: being the _Essence_ of the whole _Plant_, which nature treasureth up in these _Vessels_. So that they are, in all respects, analogous to the _Turpentine Vessels_ in _Pine_. There are divers other _Herbs_ and _Trees_, which in the like _Vessels_, contain a _Turpentine_, or rather _Aromatical Balsom_; as _Angelica_, _Helenium_ and others; the _Vessels_ being so very large, that they may be easily traced with a knife, in cutting by the length of a _Branch_ or _Stalk_.

29. §. Whether in some _Plants_, there are not more _Sorts_ of _Vessels_, in the _Barque_, than have been now mentioned, I cannot say: Though we have not much reason to doubt of it. Because we see, there is so great variety in the _Viscera_ of _Animals_. For what the _Viscera_ are in _Animals_; the _Vessels_ themselves are in _Plants_.

30. §. CONCERNING the _Form_ and _Texture_ of the _Lymphæducts_, there are some things, which though they are best observed in the _Wood_, yet in regard I am now describing the said _Vessels_, I shall here therefore add. I have already said, and shewed, in the former _Books_, That the _Lignous_ and _Towy Parts_ of all _Plants_, are _Tubulary_. And that the _Lympha_ is conveyed, by the length of a _Plant_, through an innumerable company of small _Tubes_ or _Pipes_.

31. §. The _Question_ may be yet further put: If the _Towy Parts_ of the _Barque_ are made of _Tubes_, What are these _Tubes_ themselves made up of? _I answer_, That these _Tubes_ or _Lymphæducts_, are not only themselves _Organical_; but their very _Sides_ also, seem to be composed of other _Parts_, which are _Organical_, _sc._ of _Lignous_ or _Towy Fibres_. ♦ _Tab. 40._ ♦ Which _Fibres_, standing close or contiguous in a round _Figure_, they make one _Tubulary Body_, which I call the _Lymphæduct_ of a _Plant_. And it is probable, That these _Fibres_ themselves, are also _Tubulary_. That is, that a _Lymphæduct_, is a small _Tube_, made up or composed of other, yet much smaller _Tubes_, set round together in a _Cylindrick Figure_. As if we should imagine a company of _Straws_, which are so many small _Pipes_, to be joyned and set round together, so as to make another greater _Pipe_, answerable to a _hollow Cane_. The _Cane_, I say, is as the _Lymphæduct_; and the _Straws_ are as the _Fibres_ whereof it is composed. By which also appears, the admirable smallness of these _Fibres_. For there are some _Lymphæducts_, which may be reckoned fifty times smaller than a _Horse-Hair_. Allowing therefore but Twenty of the aforesaid _Fibres_ to make a _Thred_ so big as one _Lymphæduct_; then one of the said _Fibres_, must be a Thousand times smaller than a _Horse-Hair_. That these _Fibres_, whereof the _Lymphæducts_ are made, are themselves made up of other _Fibres_, is not altogether improbable.

32. §. These _Fibres_, although parallel; yet are they not _coalescent_, but only contiguous; being contained together in a _Tubulary Figure_, by the Weftage of the _Cortical Fibres_, as in _Chapter_ the _Fourth_ will better be understood.

33. §. The first notice I took of the _Composition_ and _Texture_ of these _Vessels_, so far as the best _Glasses_ yet known, will admit; was in a very _white_ and _clear_ piece of _Ash-wood_ torn, with some care, by the length of the _Tree_, and objected to a proper _Light_. They seem also sometimes discernable in some other _clear Woods_, as in very _white Fir_, _&c._ And having formerly demonstrated, that the _Lignous Part_ of a _Plant_, is annually made or augmented out of the inner part of the _Barque_, wherein the _Lymphæducts_ always stand: we may reasonably suppose the same _Lymphæducts_ to have the like Conformation in the _Barque_, as in the _Wood_.

34. §. And I am the rather induced to believe, that I am not mistaken in this Description, upon these two Considerations. _First_, that herein the Analogy betwixt the _Vessels_ of an _Animal_ and a _Plant_, is the more clear and proper. For as the _Sanguineous Vessels_ in an _Animal_ are composed of a number of _Fibres_, set round, in a _Tubulary Figure_, together: so are these _Lymphæducts_ of a _Plant_. _Secondly_, in that herein, there is a more genuine respondence betwixt these, and the other _Vessels_ of a _Plant_ it self; _sc._, the _Aer-Vessels_; which are made up of a certain number of _Round Fibres_, standing collaterally, or side to side as I have already observed in the _Anatomy_ of _Roots_. So that it is the less strange, that the _Lymphæducts_ should be made up of _Fibres_, since the _Aer-Vessels_ are evidently so made. Only with this difference, that whereas in the _Aer-Vessels_, the _Fibres_ are postured or continued _Spirally_: here, in the _Lymphæducts_, they stand and are continued only in _straight Lines_.

35. §. THE STRUCTURE of the _Lactiferous_ and _Gum-Vessels_, which have a very ample _Bore_, is more apparent. ♦ _Tab. 20._ ♦ And, by the best _Glasses_ I have yet used, they seem to be made, chiefly, by the Constipation of the _Bladders_ of the _Barque_. That is to say, That they are so many _Chanels_, not made or bounded by any walls or sides proper to themselves, as a _Quil_ thrust into a _Cork_, and as the _Aer-Vessels_ are in the _Wood_: but only by the _Bladders_ of the _Parenchyma_; which are so postured and crouded up together, as to leave certain _Cilyndrick Spaces_, which are continued by the length of the _Barque_.

36. §. One difference betwixt the _Vessels_ or _Chanels_ now describ’d, and the Tubulary _Hollows_ and other _Apertures_ in the _Pith_, is this; That these never exist originally with the _Pith_; but are so many _Ruptures_ supervening to it in its Growth. Caused, partly, by the Stretch or Tenter it suffers from the Dilatation of the _Wood_:[60] and partly, the drying, and so the Shrinking up of its _Bladders_, and of the _Fibres_ whereof they are composed. Whereas the said _Vessels_ in the _Barque_, are many of them originally formed therewith. And those which are _post-nate_, not made by any _Rupture_, but only such a Disposition of the _Parenchymous Fibres_, and Constipation of the _Bladders_, as is thereunto convenient.

[60] _B. 1. c. 3. §. 22, & 23._

37. §. In paring the _Barque_ of a _Branch_ of _Pine_, _Sumach_, &c. they appear, neither _parallel_, nor any where _Inosculated_: but run, with some little obliquities, distinct one from another, through the length of the _Branch_: and so, we may believe, through the length of the _Tree_.

CHAP. III.

_Of the WOOD._

THE next general _Part_ of a _Branch_, is the _Wood_; which lyeth betwixt the _Barque_ and the _Pith_. And this likewise evermore consisteth of Two General _Parts_, _sc._ of a _Parenchymous Part_, and that more properly called _Lignous_. The _Parenchymous Part_ of the _Wood_, though much diversifyed, yet in the _Trunks_ of all _Trees_ whatsoever, hath this property, To be disposed into many _Rays_, or _Diametral Insertions_, running betwixt so many _Lignous Portions_, from the _Barque_ to the _Pith_: as in any of the _Quarters_ here before us may appear.

2. §. But these _Insertions_ are much diversifyed, according to the several _Sorts_ of _Plants_. So in _Barberry_, _Ash_, _Pine_, _Worm-wood_, they are less numerous. ♦ _Tab._ 22, to 35. ♦ In _Elm_, _Wallnut_, _Fig_, _Sumach_, they are more. And in _Holly_, _Pear_, _Plum_, _Apple_, _Oak_, _Hazel_, are most numerous.

3. §. The same _Insertions_, in _Barberry_, _Wormwood_, and some in _Oak_, are very Thick. In _Pine_, _Fig_, _Ash_, of a middle _Size_. In _Pear_, _Holly_, and most of them in _Oak_, are exceeding Small. ♦ _Ibid._ ♦ Again, in _Barberry_, _Elm_, _Ash_, _Sumach_, _Fig_, they are of an Equal _Size_. In _Holly_, _Hazel_, _Pear_, _Plum_, _Oak_, they are very Unequal: some of those in _Holly_, being _Four_ or _Five_ times thicker than the rest; in _Plum_, _Six_ or _Seven_ times; and in _Oak_, _Ten_ times at least.

4. §. In some _Plants_, they are Equidistant; in others, not: in some, the Great ones are Equidistant; in others, the Lesser; in others, both; in some, neither. Which _Varieties_ are not accidental; but constant to the _Species_ in which they are severally found.

5. §. They are not always visibly continued from the Circumference to the Centre of the _Wood_: but in some _Branches_, as of _Sumach_; and in most _Trunks_ of many years growth, declining, in some places, ♦ _Tab. 34._ ♦ under or over, from a Level, are thereby, upon a Transverse Section, in part cut away.

6. §. They have yet one more Diversity, which is, That in divers of the aforesaid _Branches_, they run not only through the _Wood_; but also shoot out beyond it, into some _Part_ of the _Barque_, as in _Elm_, _Sumach_, _Wormwood_, &c. ♦ _Tab. 28, 34, 35._ ♦ Whereas in _Pine_, and some of the rest they either keep not distinct from the other parts of the _Parenchyma_ of the _Barque_; ♦ _Tab. 32._ ♦ or are so small, as not to be distinguished there from.

7. §. The _Texture_ likewise of these _Insertions_ is somewhat various. ♦ _Tab. 35._ ♦ For in _Wormwood_, and most _Herbs_, they are manifestly composed of small _Bladders_: differing in nothing from those of the _Barque_ or _Pith_, saving, in their being much less. Yet in _Herbs_, they are much larger than they are in _Trees_. ♦ _Tab. 36, 37._ ♦ And in many _Trees_, as _Apple_, _Pear_, _Plum_, _Pine_, &c. they are either quite lost, or so squeezed and pressed together by the hard _Wood_ standing on both sides, as to be almost undiscernable.

8. §. So that although the _Parenchyma_ of the _Barque_ or _Pith_, and the _Insertions_ in the _Wood_, are of the same _Specifick_ Nature or Substance: yet there is this difference betwixt them; That the _Fibres_ of the former, are so Netted together, as to leave several round Vacuities; or to make a great many little _Bladders_, whereas, in the latter, they are usually so far crowded up, as to run (as when a Net is stretched out) like a _Skein_ of _Parallel Threds_.

9. §. Of these _Insertions_ in the _Wood_, it is further observable, That they do not only run betwixt the _Lignous Portions_; but that many of their _Fibres_ are likewise all along distributed to the several _Fibres_, ♦ _Tab. 40._ ♦ of which the _Lignous Portions_ consist, and are interwoven with them; both together thus making a piece of _Linsy-Woolsy Work_, or like many other _Manufactures_ in which the _Warp_ and the _Woof_ are of different Sorts of _Stuff_: as in the end of the _Fourth Chapter_ is further explained.

10. §. THE WOOD is likewise compounded of Two Sorts of _Bodies_; That which is strictly _Woody_; and the _Aer-Vessels_ mixed herewith. The true _Wood_ is nothing else but a mass of antiquated _Lymphæducts_, _viz._ those which were originally placed on the inner Margin of the _Barque_. For in that place, there grows, every year, a new _Ring_ of _Lymphæducts_. Which losing its original softness by degrees, at the latter end of the year, is turned into a dry and hard _Ring_ of perfect _Wood_.

11. §. So that every year, the _Barque_ of a _Tree_ is divided into Two Parts, and distributed two _contrary_ ways. The outer Part falleth off towards the _Skin_; and at length becomes the _Skin_ it self. In like manner, as hath been observed of the _Skin_ of the _Root_. Or as the _Cuticula_ in _Animals_, is but the efflorescence of the _Cutis_. I say, that the elder _Skin_ of a _Tree_, is not originally made a _Skin_; but was once, some of the _midle_ part of the _Barque_ it self, which is annually cast off, and dryed into a _Skin_: even as the very _Skin_ of an _Adder_, upon the gradual generation of a new one underneath, in time, becomes a _Slough_. The inmost portion of the _Barque_, is annually distributed and added to the _Wood_: the _Parenchymous Part_ thereof making a new addition to the _Insertions_ within the _Wood_; and the _Lymphæducts_ a new addition to the _Lignous pieces_ betwixt which the _Insertions_ stand. So that a _Ring_ of _Lymphæducts_ in the _Barque_ this year, will be a _Ring_ of _Wood_ the next; and so another _Ring_ of _Lymphæducts_, and of _Wood_, successively, from year to year. So the _Table_, for an _Apple-Branch_, ♦ _Tab. 25, 24, 34, 28._ ♦ sheweth a quarter of a _Slice_ of a _Branch_ cut transversly, of Three years growth: That of _Barbery_, of Two; That of _Sumach_, of One only; That of _Elm_, of Five.

12. §. Hereby two things maybe the better noted. First, the difference betwixt the degrees of the _annual_ growths of several _Trees_: three years growth in an _Oak_, being as thick as five in an _Elm_. ♦ _Tab. 33, 28._ ♦ Secondly, the difference betwixt the _Annual_ growths of the _same Tree_; being not of a constant proportion, but varying in thickness, as it should seem, according to the _season_ of the year: whereby it may appear, what _season_, or kind of year, doth most of all favour, the latitudinal growth, or the _thickening_ of any _Tree_.

13. §. The _Lymphæducts_ thus antiquated or turned into _Wood_, do rarely, if ever, _Bleed_: but only transmit a kind of _Dewy_ or _Vaporous Sap_. And some of them, as in the _Heart_ of some _Trees_, it is probable, That they transmit not any _Sap_, either in the form of a _Liquor_, or a _Vapour_: and so being gradually deprived of their _Watery Parts_, become the _Heart_.

14. §. There is this further variety in the _Wood_; represented in _Walnut_, _Fig_ and _Oak_. That some certain parcels hereof, make either several small and white _Rings_, as in _Oak_; or else divers white and crooked _Parcels_, transverse to the _Insertions_, as in _Wallnut_ and _Fig_. ♦ _Tab. 30, 31, 33._ ♦ For it seemeth, that, at least,in many _Trees_, some portion of all the _Kinds_ of _Vessels_ in the _Barque_, are not only annually distributed to the _Wood_, but do likewise therein retain the same, or somewhat like _Position_, which they originally had in the _Barque_. So that as all those bigger and darker Portions of the _Wood_, were originally, the _Radiated Lymphæducts_ of the _Barque_: so the little white _Circles_, or _Parcels_ of _Circles_, in the same _Wood_, were originally another sort of _Sap-Vessels_ in the _Barque_, _sc._ those which have a circular Position therein.

15. §. In the _Branches_ of _Fir_, _Pine_, and others of the same _Kindred_, there are some few _Turpentine-Vessels_ scattered up and down the _Wood_; ♦ _Tab. 32._ ♦ and represented by the larger Black Spots. Which _Vessels_ are _eadem numero_, the self same, which did once appertain to the _Barque_; and do even here also in the _Wood_, contain and yield a liquid _Turpentine_. Only, being pinched up by the _Wood_, they are become much smaller _Pipes_.

16. §. THE _Aer-Vessels_, with the _Insertions_, and true _Wood_, altogether make up That, which is commonly called, The _Wood_ of a _Tree_. The _Aer-Vessels_ I so call, not in that they never contain any _Liquor_; but, because all the principal time of the growth of a _Plant_, when the _Vessels_ of the _Barque_ are filled with _Liquor_, these are filled only with a _Vegetable Aer_.

17. §. In almost all _Plants_, not one in some hundreds excepted, this is proper to the _Aer-Vessels_; To have a much more ample _Bore_ or _Cavity_, than any other in the _Wood_. In the _Wood_, I say; for in the _Barque_, there are many _Sap-Vessels_ bigger than the biggest _Aer-Vessels_ that be.

18. §. The Varieties hereof are very many; in respect both of their _Number_, _Size_, and _Position_; being, as to these, the same, in no two _Sorts_ of _Plants_ whatsoever. First in respect of their _Number_. So in _Hazel_, _Apple_, _Pear_, they are very numerous; but in different degrees: and are represented in the _Figures_ already referred to, by all the black spots in the _Wood_. ♦ _Tab. 23, 25, 26. 22, 24, 27. 29, 30, 33. 32._ ♦ In _Holly_, _Plum_, _Barberry_ somewhat numerous. In _Oak_, _Ash_, _Walnut_ fewer. In _Pine_, and others of that _Kindred_, very few; _sc._ fewer than in any other kind of _Plant_.

19. §. Secondly, in respect of their _Size_; which from the first or greatest, to the least, may be computed easily to about Twenty Degrees. Thus, many of those in _Elm_, _Ash_, _Wallnut_, _Fig_, _Oak_, are very large. In _Barberry_, _Plum_, not so large. In _Hazel_, _Sumach_, smaller. In _Holly_, _Pear_, of a still smaller _Size_. ♦ _Tab. 28, 33. 22, 26._ ♦ So that many of those in _Elm_, or _Oak_, are Twenty times bigger, than those in _Holly_ or _Pear_.

20. §. In an ordinary joynted _Cane_, they are so wide, that if you take one a yard, or a yard and ½ long, and putting one end into a Basin of Water, you blow strongly at the other; your Breath will immediately pass, through the _Aer-Vessels_, the length of the _Cane_, so as to raise up the Water into a great many _Bubbles_.

21. §. And as they have a different Size in divers Kinds of _Plants_; so likewise, according to the place where they stand, in the self same. So in _Holly_, _Hazel_, _Apple_, their _Size_ is more equal throughout the bredth of the _Tree_. ♦ _Tab. 22, 23, 25. 24, 28, 29. 33._ ♦ But in _Barberry_, _Elm_, _Oak_, _Ash_, very different: Not fortuitously, but always much after the same manner. For in all the last named _Branches_, the _Aer-Vessels_ stand in the inner _margin_ of each annual _Ring_, are all vastly bigger, than any of those that stand in the outer part of the _Ring_.

22. §. Thirdly, these _Aer-Vessels_ are also different in their _Situation_. So in _Apple_, _Wallnut_, _Fig_, they are spread all abroad in every annual _Ring_; ♦ _Tab. 25, 30, 31._ ♦ not being posited in any one certain _Line_. In others, they keep more within the compass of some _Line_ or _Lines_; either _Diametral_, or _Peripheral_. ♦ _Tab. 22. 23, 32._ ♦ So in _Holly_ they are _Radiated_, or run in even _Diametral Lines_ betwixt the _Pith_ and the _Barque_. So also are some of them in _Hazel_; and some few in _Wallnut_.

23. §. Whether they stand _Irregularly_, or are _Radiated_, it is to be noted, That Nature, for the most part, so disposeth of them, that many of them may still stand very near the _Insertions_. So in _Apple_, she will rather decline making an even _Line_; or in _Holly_, will rather break that _Line_ into _Parcels_, than that the _Aer-Vessels_ shall stand remote from the _Insertions_. To what end this is done, shall be said hereafter.

24. §. Again, in _Ash_, the _Aer-Vessels_ are none of them _Radiated_, but most of them stand in _Circles_ on the inner _Margin_ of every annual _Ring_. ♦ _Tab. 24. 29. 28. 26, 27._ ♦ Which _Circle_ is sometimes very thick, as in _Ash_ and _Barberry_. In others but thin, the _Vessels_ standing, for the most part, single throughout the _Circles_; as in _Elm_. Sometimes again, they both make a _Circle_, and are also spread abroad; as in _Pear_ and _Plum_.

25. §. Those likewise which are spread abroad, are sometimes _Regularly_ posited. ♦ _Tab. 24._ ♦ So in _Barberry_, besides those larger, that make the _Circle_, there are other smaller ones, that stand, in oblique _Lines_, athwart one another; almost like a _Bend_, or sometimes, an entire or broken _Saltyr_ in an _Escutcheon_. ♦ _Tab. 33. 38._ ♦ In _Oak_, they make rather certain _Columns_, in the posture of the _Pale_. And in _Elm_, they make, as it were, many _cross Parcels_, in the posture of the _Fess_.

26. §. This great difference in the _Size_ and _Position_ of the _Aer-Vessels_, in the same individual _Plant_, is one ground, for which, I think it probable, That there are _divers Kinds_ of _Aer-Vessels_, as well as of _Sap-Vessels_. Even as in _Animals_, there are divers _Kinds_ of _Organs_ for _Spiration_, and the separation of _Aer_: _Fishes_ having their _Branchiæ_; _Land-Animals_ their _Lungs_; and those in _Frogs_, _&c._ being of a somewhat peculiar _Kind_.

27. §. THE _Form_ and _Texture_ of these _Vessels_, and the various ways whereby they may be best observed, I have already described and shewed in my _Anatomy_ of _Roots_. ♦ _P. 1. c. 4._ ♦ As to their _Form_, one thing remarqued was this; That they are never _Ramified_, but distinctly continued from one end of a _Plant_, small or great, to the other: as the _Nerves_ are in _Animals_. A further and easie proof whereof, may be made, only by holding up a piece of an ordinary _Cane_, about ½ a foot long, cut very smooth at both ends, against a full light: whereupon, if you keep it in a straight _Line_ betwixt the _Light_, and the cast of your _Eye_, and then look steadily, you may see quite through it, that is, through the _Aer-Vessels_, which run straight along the _Cane_ from end to end.

28. §. As to their _Texture_; whereas, oftentimes, the _Aer-Vessels_ appear to be _unroaved_ in the form of a very small _Plate_, it is to be noted, That it is not only of different bredth, in divers _Plants_, and usually much broader in the _Root_, than in the _Trunk_: but also, that in the _Trunk_, many times, the said _Vessels_ are unroaved or resolved, not in the form of a _Plate_, but of a _Round-Thred_. The Causes of which Diversity, are principally Three; _viz._ The _Weftage_ of the _Fibres_ of which the _Aer-Vessels_ consist; The deference betwixt the said _Fibres_, or betwixt the _Warp_ and the _Woof_; And the different _Kinds_ of _Woof_.

29. §. By the _Weftage_ of the _Fibres_, it is, That the _Vessels_, oftentimes, _unroave_ in the form of a _Plate_. As if we should imagine a piece of fine narrow _Ribband_, to be woun’d spirally, and Edg to Edg, round about a Stick; and so, the Stick being drawn out, the _Ribband_ to be left in the _Figure_ of a _Tube_, answerable to an _Aer-Vessel_. For that which, upon the _unroaving_ of the _Vessel_, seems to be a _Plate_, ♦ _Tab. 39._ ♦ or one single _Piece_, is, as it were, a _Natural Ribband_, consisting of several Pieces, that is, a certain number of _Threds_ or _Round Fibres_, standing parallel, as the _Threds_ do in an _Artificial Ribband_. And as in a _Ribband_, so here, the _Fibres_ which make the _Warp_, and which are Spirally continu’d; although they run parallel, yet are not coallescent; but conteined together, by other Transverse _Fibres_ in the place of a _Woof_.

30. §. And as the said _Fibres_ are transversly continued, thereby making a _Warp_ and _Woof_: So are they (as in divers woven _Manufactures_) of very different _Bulk_; those of the Former, being much bigger, and therefore much stronger, than those of the Latter. By which means, as _Cloth_ or _Silk_ will often Tear one way, and not another; so here, while the _Warp_ or those _Fibres_ which are Spirally continued, are usually _unroaved_ without breaking; those smaller ones, by which they are _stitched_ or _woven_ together, easily tear in sunder all the way.

31. §. And because the _Fibres_ of the _Woof_, are themselves also of different _Bulk_; therefore it is, That where they are more sturdy, as usually in the _Root_, they require a greater quantity of _Warp_, that is, a broader _Plate_, to overmatch them. Whereas, where they are more extream small, as in the _Trunk_ and _Leaves_, one _Thred_ of the _Warp_, that is, one _Spiral Fibre_, will be strong enough of it self, and so, sometimes, be singly _unroav’d_.

32. §. From the extream Tenuity of these _Fibres_, it is, That they are very rarely discern’d, and not without the greatest difficulty. As also, from their great Tenderness; whereby not enduring to be drawn out, they all break off close to the Sides of the _Spiral ones_. In the _Pith_, the like Transverse _Fibres_ are a little more visible: which first conducted Me to the notice of them here also.

33. §. All the _Fibres_ of the _Aer-Vessels_, both the _Warp_ and the _Woof_, are of the same Substantial Nature with the _Pith_ and the other _Parenchymous Parts_ of a _Plant_. From whence it is, That whereas the _Towy Parts_ of a _Plant_, whereof all _Linen Manufactures_ are made, are very _Strong_ and _Tough_; these, as is abovesaid, are extream _Tender_ and _Brittle_, like those of the _Pith_ and all the _Pithy Parts_. To which therefore, the _Aer-Vessels_ are to be referr’d. And the _Content_ of both, is oftentimes the same.

34. §. From whence, we have a further proof of what I have formerly asserted, which is, That in all _Plants_, there are _Two_ Substantially different _Parts_, ♦ _B. 1. c. 7. §. 13. 14._ ♦ and no more than _Two_, _viz._ the _Pithy_, and the _Towy_ or _Lignous Parts_.

35. §. From hence also we have some ground to conjecture, That so many of the _Aer-Vessels_, at least, which are not formed with the seed, but _post-nate_, are originated from the _Parenchymous Parts_; which seem by some alteration in the _Quality_, _Position_ and _Texture_ of the _Fibres_, to be Transformed into _Aer-Vessels_, as _Caterpillars_ are into _Flies_. And as the _Pith_ it self, by the Rupture and Shrinking up of several _Rows_ of _Bladders_, doth oftentimes become Tubulary: So is it also probable, that in the other _Parenchymous Parts_, one single _Row_ or _File_ of _Bladders_ evenly and perpendicularly piled; may sometimes, by the shrinking up of their Horizontal _Fibres_, all regularly break one into another and so make one _continued Cavity_; or a _Tube_, whose _Diametre_ is the same with that of the _Bladders_, wherof it is composed. All which, will appear more probable, and what hath been said, be yet better understood, when we come, in the next _Chapter_, to the Description of the _Pith_.

CHAP. IV.

_Of the PITH._

THE Third General _Part_ of a _Branch_ is the _Pith_. Which though it have a different name from the _Parenchyma_ in the _Barque_, and the _Insertions_ in the _Wood_; yet, as to its _Substance_, it is the very same with them both. Whereof there is a double evidence, _sc._ their _Continuity_, and the sameness of their _Texture_. Their _Texture_ shall be shewed presently. As to their _Continuity_, it is to be noted, That as the _Skin_ is continuous with the _Parenchyma_ of the _Barque_; and this _Parenchyma_ likewise, with the _Insertions_ in the _Wood_; so these _Insertions_ again, running through the _Wood_, are also continuous with the _Pith_. So that the _Skin_, _Parenchyma_, _Insertions_, and _Pith_, are all _One entire piece of Work_; being only filled up, in divers manners, with the _Vessels_.

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.

An Account of the

VEGETATION

OF

TRUNKS

Grounded upon the foregoing

ANATOMY.