The proportions of this Cortical Body are various: If thin, ’tis called a Barque; & thought to serve to no other end, than what is usually ascrib’d to it as a Barque; which is a narrow conceit: If a Bulky Body in comparison with that within it, as in the young Roots of Cychory, Asparagus, &c. ’tis here, because the fairest, therefore taken for the prime Part; which, though, as to Medicinal use, it is; yet, as to the private use of the Plant, not so. The Colour hereof, though it be originally white, yet in the continued growth of the Root, divers Tinctures, as yellow in Dock, red in Bistort, are thereinto introduced.
Next within this Part stands the Lignous Body; the Original whereof, as of the two former, is from the Seed; or, the Seminal Roots of both the Lobes, being united in the Radicle, and with its Parenchyma co-extended, is here in the Root the Lignous Body.
The Contexture hereof is, in many of its parts, much more close than that of the Cortical; and their Pores very different: For whereas those of the Cortical are infinitely numerous, these of the Lignous are in comparison, nothing so. But these, although fewer, yet are they many of them more open, fair, and visible: as in a very thin Slice cut athwart the young Root of a Tree, and held up against the Light, is apparent: Yet not in all equally, in Coran-Tree, in Goosberry-Tree, &c. less; in Oak, Plums, and especially Damascens, more; in Elder, Vines, &c. more conspicuous. And as they are different in number and size, so also (whereon the numerousness of the Pores of the Cortical Body principally depends) in their shape. For whereas those of the Cortical Body are extended much alike both by the length and breadth of the Root; these of the Lignous are only by the length; which, especially in Vines and some other Roots, is evident. Of these Pores, ’tis also observable, that although in all places of the Root they are visible, yet most fair and open about the Fibrous Extremities of some Roots (and in many Roots higher) where there is no Pith. These Pores, as they shew in young Roots of Trees, [see in Fig. 6, & 7].
This Lignous Body lieth with all its Parts, so far as they are visible, in a Circle or Ring; yet are there divers extream small Fibres thence shooting, usually mixed with the Cortical Body; and by the somewhat different colour of the said Cortical Body where they stand, may be noted these Fibres; the Cortical Body and Skin all together, properly make the Barque.
The proportion betwixt this Lignous Body and the Cortical, is various, as was said; yet in this, constant, sc. that in the fibrous, and smaller Parts of the Root, the Lignous Body is not only in compass, but in quantity the less; running like a slender Wyer or Nerve through the other surrounding it. They stand both together pyramidally, which is most common to Infant-Roots, but also to many other.
The next Part observable in the Root, is the Insertment. The existence hereof, so far as we can yet observe, is sometimes in the Radicle of the Seed it self; I cannot say alwayes. As to its substantial nature, we are more certain; that it is the same with that of the Parenchyma of the Radicle; being alwayes at least augmented, and so, in part, originated from the Cortical Body, and so, at second hand, from the said Parenchyma: For in dissecting a Root, we find, that the Cortical Body doth not only environ the Lignous, but is also wedg’d, and in many pieces inserted into it; and that the said inserted pieces, make not a meer Indenture, but transmit and shoot themselves quite through as far as the Pith; which in a thin Slice cut athwart the Root as so many lines drawn from the Circumference towards the Center, shew themselves. [See Fig. 6, & 7.]
The Pores of the Insertment are sometimes, at least, extended somewhat more by the breadth of the Root, as about the top of the Root of Borage may be seen; and are thus different from those of the Cortical Body, which are extended by the length and breadth much alike; and from those of the Lignous, being only by its length.
The number and size of these Insertions are various. In Hawthorn, and some others, and especially Willows, they are most extream small; in Cherries and Plums they are large; and in Damascens especially, very fairly apparent. In the Roots of small Plants they are generally more easily discoverable; which may lead to the observation of them in all.
These Insertions, although they are continuous through both the length and breadth of the Root; yet not so in all Parts, but by the several shootings of the Lignous Body are frequently intercepted. For of the Lignous Body it is (here best) observable, That its several shootings, betwixt which the Cortical is inserted, are not throughout the Root wholly distinct; but that all along being enarch’d, the Lignous Body, both in length and breadth, is thus disposed into Braces or Osculations. Betwixt these several shootings of the Lignous Body thus osculated, the Cortical shooting, and being also osculated answerably Brace for Brace, that which I call the Insertment is fram’d thereof.