_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.
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 (so as to take the _Pith_ in also) from
its _Inner_ or _Central parts_. Divers whereof 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 _Lignous Body_
of the _Trunk_ is sometimes principally from those Fibrous _Shoots_ which
run along the _Pith_ in the _Root_.
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 parts 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 Parts, 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_.
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, bind and throng each other into a Knot; through which Knot the
_Sap_ being strain’d, ’tis thus in due moderation & purity delivered up
into the Branch.
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.
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 _Elder
Branch_, and the _Basis_ of the Stalk of the _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,
as larger, so more hardy. The manner and uses of the position of every
_Germen_, considered as after it becomes a _Branch_, hath already been by
the Ingenious Mr. _Sharrock_ very well observed; to whom I refer.
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, & 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 continuations of the _Cortical Body_, or inner part of the
_Barque_ from the _Branch_ into it self, as in most Plants with a fat
Leaf, may easily be seen.
The Fibres of the _Leaf_ neither shoot out of the _Branch_ nor _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 Cord of a Circle; as in _Cycory_, _Endive_, _Cabbage_,
&c. may be observed: And if the Leaf have but one main Nerve, that also
is postur’d in a Circular or Lunar Figure; as in _Mint_ and others. The
usual number of these Nerves or Fibres is 3, 5, or 7. See the _Figures_
from 20, to 29.
The reason of the said Positions of the Fibres in the _Stalk_ of the
_Leaf_, is for its more erect growth, and greater strength; which, were
the position of the said Fibres 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_, we may better conceive.
As likewise for the security of its _Sap_: For by this means it is, that
the several Fibres, and especially the main or middle Fibre of the Leaf,
together with a considerable part of the _Cortical Body_, are so disposed
of, as to jut out, not from its upper, but its back, or nether plain.
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.
These Fibres are likewise the immediate visible Cause of the shape of the
Leaf: For if the nethermost Fibre or Fibres in the Stalk be in proportion
greater, the Leaf is long, as in _Endive_, _Cycory_, and others: If all
of a more equal size, it spreads rounder, as in _Ivy_, _Doves-foot_,
_Colts foot_, &c. And although a _Dock-Leaf_ be very long, whose Fibres
notwithstanding, as they stand higher in the Stalk, are disposed into a
Circle all of an equal size; yet herein a peculiar fibre, standing in the
Center betwixt the rest, and running through the length of the Leaf, may
be observed.
In correspondence also to the size and shape of these Fibres, is the Leaf
flat: In that either they are very small, or if larger, yet they never
make an entire Circle or Ring; but either half of one, as in _Borage_, or
at most three parts of one, as in _Mullen_, may be seen. For if either
they were so big, as to contain; or so entire, as perfectly to include
a _Pith_, the Energy of the _Sap_ in that _Pith_, would cause the said
_Lignous Ring_ to shoot forth on every side, as it doth in the _Root_ or
_Trunk_: But the said Fibres being not figur’d into an entire Ring, but
so as to be open; on that hand therefore where open, they cannot shoot
any thing directly from themselves, because there they have nothing to
shoot; and the _Sap_ having also a free vent through the said opening,
against that part therefore which is thereunto opposite, it can have no
force; and so neither will they shoot forth on that hand; and so will
they consequently that way only which the force of the _Sap_ directs,
which is only on the right and left.
The several Fibres in the Stalk, are all inosculated in the Leaf, with
very many Sub-divisions; according as these Fibres are inosculated
near, or at, or shoot directly to the edge of the Leaf, is it even or
scallop’d. Where these Inosculations are not made, there we have no
_Leaves_, but only a company of _Ramulets_, as in _Fennel_.
The Formations and Fouldings of Leaves have one Date, or are the
contemporary works of Nature; each Leaf obtaining its distinct shape,
and proper posture together; both being perfect, not only in the outer,
but Central and minutest Leaves, which sometimes are five hundred times
smaller than the outer; both which in the Cautious opening of a _Germen_
may be seen.
Nor is there greater Art in the Forms, than in the Foulds or Postures
of _Leaves_; both answerably varying, as this or that way they may be
most agreeable. Of the _Quincuncial_ posture, so amply instanc’d in by
the Learned Dr. _Brown_, I shall omit to speak. Others there are, which
though not all so universal, yet equally necessary where they are; giving
two general advantages to the Leaves, Elegancy and Security, _sc._ in
taking up, so far as their Forms will bear, the least room; and in being
so conveniently couch’d, as to be capable of receiving protection from
other parts, or of giving it to one another; as for instance,
First, There is the _Plain-Lap_, where the Leaves are all laid
somewhat convexly one over another, but not plaited; being to the
lengthy, breadth and number of Leaves most agreeable; as in the Buds
of _Pear-tree_, _Plum-tree_, &c. But where the Leaves are not thick
set, as to stand in the _Plain-lap_, there we have the _Plicature_;
as in _Rose-tree_, _Strawberry_, _Cinquefoyl_, _Burnet_, &c. For the
Leaves being here plaited, and so lying in half their breadth, and
divers of them thus also collaterally set together, the thickness of
them all, and half their breadth, are much alike dimensions; by which
they stand more secure within themselves, and in better consort with
other _Germen-Growths_ in the same Truss. If the Leaves be much indented
or jagg’d, now we have the same Duplicature; where there are divers
Plaits in the same Leaf, or Labels of a Leaf, but in distinct Sets, a
lesser under a greater; as in _Tansey_, &c. When the Leaves stand not
collaterally, but single, and that they are moreover very broad; then
we have the _Multiplicature_; as in _Gooseberries_, _Mallows_, &c. the
Plaits being not only divers in the same Leaf, but of the same set
continuant, and so each Leaf gather’d up in five, seven, or more Foulds,
in the same manner as our Gentlewomens Fans: Where either the thickness
of the Leaf will not permit a _flat lap_, or the fewness of their
number, or the smallness of their Fibres, will allow the _Rowl_, there
this may be observed; which is sometimes single, as in _Bears-Ears_;
sometimes double, the two _Rowls_ beginning at each edge of the Leaf,
and meeting in the middle. Which again, is either the _Fore-Rowl_, or
the _Back-Rowl_. If the Leaf be design’d to grow long, now we have the
_Back-Rowl_, as in _Docks_, _Primroses_, &c. For the main Fibres, and
that with a considerable part of the _Cortical Body_ standing prominent
from the _Back-plain_ of the Leaf, they thus stand securely couch’d up
betwixt the two _Rowls_; on whose security the growth of the Leaf in
length depends. But _Bears-Ears_, _Violets_, &c. upon contrary respects,
are rowled up inwards. Lastly, there is the _Tre-Rowl_, as in _Fern_;
the _Labels_ whereof, though all rowled up to the _main Stem_, yet could
not stand so firm and secure from the Injuries either of the Ground
or Weather, unless to the _Rowls_ in breadth, that by the length were
super-induc’d; the _Stalk_ or _main Stem_ giving the same protection
here, which in other Plants by the Leaves, or some particular _Mantling_,
is contriv’d.
For according to the Form and Foulding of every Leaf or _Germen_, is its
protection order’d; about six wayes whereof may be observ’d; _sc._ by
_Leaves_, _Surfoyles_, _Interfoyles_, _Stalks_, _Hoods_ and _Mantlings_.
To add to what we have above given, one or two Instances. Every Bud,
besides its proper Leaves, is covered with divers Leafy _Pannicles_ or
_Surfoyls_; which, what the Leaves are to one another, are that to them
all: For not opening except gradually, they admit not the Weather, Wet,
Sun or Ayr, to approach the Leaves, except by degrees respondent, and as
they are leisurely inur’d to bear them. Sometimes, besides _Surfoyls_,
there are also many _Interfoyls_ set betwixt the Leaves, from the
Circumference to the Center of the _Bud_; as in the _Hasel_: For the
Fibres of these Leaves standing out so far from a plain surface; they
would, if not thus shelter’d, lie too much expos’d and naked to the
Severities of the Weather. Where none of all the Protections above-named,
are convenient, there the Membranes of the Leaves by continuation in
their first forming (together with some Fibres of the _Lignous Body_) are
drawn out into so many _Mantles_ or _Veins_; as in _Docks_, _Snakeweed_,
&c. For the Leaves here being but few, yet each Leaf and its Stalk being
both exceeding long, at the bottom whereof the next following Leaf still
springs up; the form and posture of all is such, as supersedes all the
other kinds of protection, and so each Leaf apart is provided with a Veil
to it self.
The Uses of the Leaves, I mean in respect of their service to the Plant
it self, are these; first, for Protection, which, besides what they give
to one another, they afford also to the _Flower_ and _Fruit_: To the
_Flower_ in their Foulds; that being, for the most part, born and usher’d
into the open Ayr by the _Leaves_. To the _Fruit_, when afterwards they
are display’d, as in _Strawberries_, _Grapes_, _Rasps_, _Mulberries_,
&c. On which, and the like, should the Sun-Beams immediately strike,
especially while they are young, they would quite shrivel them up;
but being by the Leaves screened off, they impress the circumjacent
Ayr so far only as gently to warm the said Fruits, and so to promote
their Fermentation and Growth. And accordingly we see, that the Leaves
above-named are exceeding large in proportion to the _Fruits_: whereas
in _Pear-trees_, _Apple-trees_, &c. the _Fruit_ being of a solider
_Parenchyma_, and so not needing the like protection, are usually equal
with, and often wider in Diameter than the _Leaves_.
Another use is for Augmentation; or, the capacity for the due spreading
and ampliation of a Tree or Plant, are its Leaves: For the _Lignous
Body_ being divided into small Fibres, and these running all along their
lax and spongie _Parenchyma_; they are thus a Body fit for the imbibition
of _Sap_ and easie growth. Now the _Sap_ having a free reception into the
Leaves, it still gives way to the next succeeding in the _Branches_ and
_Trunk_, and the voyding of the _Sap_ in these, for the mounting of that
in the _Root_, and ingress of that in the Mould. But were there no Leaves
to make a free reception of _Sap_, it must needs be stagnant in all the
parts to the _Root_, and so the _Root_ being clogg’d, its fermenting and
other Offices will be voyded, and so the due growth of the whole. As in
the motion of a Watch, although the original term thereof be the Spring,
yet the capacity for its continuance in a due measure throughout all the
Wheels, is the free and easie motion of the Ballance.
Lastly, As the Leaves subserve the more copious advancement, so the
higher purity of the _Sap_: For this being well fermented both in the
Root, and in its Ascent through the _Trunk_, and so its Parts prepar’d
to a farther separation; the grosser ones are still deposited into the
Leaves; the more elaborate and essential only thus supplied to the
_Flower_, _Fruit_ and _Seed_, as their convenient Aliment. Whence it
is, that where the _Flowers_ are many and large, into which the more
odorous Particles are copiously receiv’d, the green Leaves have little
or no smell; as those of _Rose-tree_, _Carnations_, _French-Marigold_,
_Wood-bind_, _Tulips_; &c. But on the contrary, where the Flowers are
none or small, the green Leaves themselves are likewise of a strong
savour; as those of _Wormwood_, _Tansie_, _Baum_, _Mint_, _Rue_,
_Geranium Moschatum_, _Angelica_, and others.
_An Appendix._
_Of Thorns, Hairs and Globulets._
_Thorns_ are of two kinds, _Lignous_ and _Cortical_. Of the first are
such as those of the _Hawthorn_, and are constituted of all the same
substantial Parts whereof the _Germen_ it self, and in a like proportion:
which also in their Infancy are set with the resemblances of divers
minute Leaves. In affinity with these are the _Spinets_ or _Thorny
Prickles_ upon the Verges and Tops of divers Leaves, as of _Barberry_,
_Holly_, _Thistle_, _Furze_, and others; all which I think are the
filamentous extremities of the _Lignous Body_ sheathed in the _Skin_.
_Cortical Thorns_ are such as those of the _Rasberry_ Bush, being not,
unless in a most extraordinary small proportion propagated from the
_Lignous Body_, but almost wholly from the _Cortical_ and _Skin_, or from
the _Barque_.
The growth of this _Thorn_ may farther argue what in the Second Chapter
we supposed; _sc._ That as the proper tendency of the _Lignous Body_, is
to ascend, so of the _Cortical_ to descend. For as the _Lignous Thorn_,
like other Parts upon the _Trunk_, in its growth ascends; this being
almost wholly _Cortical_, pointeth downward. The use of _Thorns_ the very
Ingenious Mr. _Sharrock_ observed.
Upon the Leaves of divers Plants two Productions shew themselves, _sc._
_Hairs_ and _Globulets_. Of _Hairs_, only one kind is taken notice of,
although they are various. Ordinarily they are plain; which when fine and
thick set, as on most _Hairy Buds_; or fine and long, as on those of the
_Vine_, we call them _Down_.
But sometimes they are not plain, but branched out, from the bottom
to the top, reciprocally on every side, in some resemblance to a
_Stags-Horn_; as in _Mullen_. And sometimes they are _Astral_, as upon
_Lavender_, and some other Leaves, and especially those of _Wild Olive_;
wherein every _Hair_ rising in one round entire Basis a little way above
the Surface of the Leaf, is then disparted. Star-like, into several,
four, five or six points, all standing at right Angles with the said
perpendicular Basis.
The Uses of Hairs are for Distinction and Protection. That of Distinction
is but secondary, the Leaves being grown to a considerable size. That of
Protection is the prime, for which they were originally form’d together
with the Leaves themselves, and whose service they enjoy in their
Infant-estate: For the _Hairs_ being then in form of a _Down_, alwayes
very thick set, thus give that protection to the Leaves, which their
exceeding tenderness then requires; so that they seem to be vested with a
Coat of _Frieze_, or to be kept warm, like young and dainty Chickens, in
Wooll.
_Globulets_ are seen upon _Orach_, both Garden and wild; and yet more
plainly on _Mercury_ or _Bonus Henricus_. In these, growing almost upon
the whole Plant, and being very large, they are by all taken notice of.
But strict Observation discovers, that these _Globulets_ are the
natural and constant Off-spring of very many other Plants. Both these
_Globulets_, and likewise the diversity of _Hairs_, I find the Learned
Mr. _Hook_ hath already observed. They are of two kinds; _Transparent_,
as upon the Leaves of _Hysop_, _Mint_, _Baume_, and many more: _White_,
as upon those of _Germander_, _Sage_, and others. All which, though
the naked Eye will discover, yet by the help of Glasses we may observe
most distinctly. The use of these we suppose the same with those of the
_Flower_, whereof we shall speak.