This Beard of a wild Oat, is a body of a very curious structure, though to the naked Eye it appears very slight, and inconsiderable, it being only a small black or brown Beard or Bristle, which grows out of the side of the inner Husk that covers the Grain of a wild Oat; the whole length of it, when put in Water, so that it may extend it self to its full length, is not above an Inch and a half, and for the most part somewhat shorter, but when the Grain is ripe, and very dry, which is usually in the Moneths of July, and August, this Beard is bent somewhat below the middle, namely, about ⅖ from the bottom of it, almost to a right Angle, and the under part of it is wreath’d lik a With; the substance of it is very brittle when dry, and it will very easily be broken from the husk on which it grows.

If you take one of these Grains, and wet the Beard in Water, you will presently see the small bended top to turn and move round, as if it were sensible; and by degrees, if it be continued wet enough, the joint or knee will streighten it self; and if it be suffer’d to dry again, it will by degrees move round another way, and at length bend again into its former posture.

If it be view’d with an ordinary single Microscope, it will appear like a small wreath’d Sprig, with two clefts; and if wet as before, and then look’d on with this Microscope, it will appear to unwreath it self, and by degrees, to streighten its knee, and the two clefts will become streight, and almost on opposite sides of the small cylindrical body.

If it be continued to be look’d on a little longer with a Microscope, it will within a little while begin to wreath it self again, and soon after return to its former posture, bending it self again neer the middle, into a kind of knee or angle.

[Schem. 15.]
Fig. 2.

Several of those bodies I examin’d with larger Microscopes, and there found them much of the make of those two long wreath’d cylinders delineated in the second Figure of the 15. Scheme, which two cylinders represent the wreathed part broken into two pieces, whereof the end AB is to be suppos’d to have join’d to the end CD, so that EACF does represent the whole wreath’d part of the Beard, and EG a small piece of the upper part of the Beard which is beyond the knee, which as I had not room to insert, so was it not very considerable, either for its form, or any known property; but the under or wreathed part is notable for both: As to its form, it appear’d, if it were look’d on side-ways, almost like a Willow, or a small tapering rod of Hazel, the lower or bigger half of which onely, is twisted round several times, in some three, in others more, in others less, according to the bigness and maturity of the Grain on which it grew, and according to the driness and moisture of the ambient Air, as I shall shew more at large by and by.

The whole outward Superficies of this Cylindrical body is curiously adorned or fluted with little channels, and interjacent ridges, or little protuberances between them, which run the whole length of the Beard, and are streight where the Beard is not twisted, and wreath’d where it is, just after the same manner: each of those sides is beset pretty thick with small Bristes or Thorns, somewhat in form resembling that of Porcupines Quills, such as aaaaa in the Figure; all whose points are directed like so many Turn-pikes towards the small end or top of the Beard, which is the reason, why, if you endeavour to draw the Beard between your fingers the contrary way, you will find it to stick, and grate, as it were, against the skin.

The proportion of these small conical bodies aaaaa to that whereon they grow, the Figure will sufficiently shew, as also their manner of growing, their thickness, and nearness to each other, as, that towards the root or bottom of the Beard, they are more thin, and much shorter, insomuch that there is usually left between the top of the one, and the bottom of that next above it, more then the length of one of them, and that towards the top of the Beard they grow more thick and close (though there be fewer ridges) so that the root, and almost half the upper are hid by the tops of those next below them.

I could not perceive any transverse pores, unless the whole wreath’d part were separated and cleft, in those little channels, by the wreathing into so many little strings as there were ridges, which was very difficult to determine; but there were in the wreathed part two very conspicuous channels or clefts, which were continued from the bottom F to the elbow EH or all along the part which was wreath’d, which seem’d to divide the wreath’d Cylinder into two parts, a bigger and a less; the bigger was that which was at the convex side of the knee, namely, on the side A, and was wreath’d by OOOOO; this, as it seem’d the broader, so did it also the longer, the other PPPPP, which was usually purs’d or wrinckled in the bending of the knee, as about E, seem’d both the shorter and narrower, so that at first I thought the wreathing and unwreathing of the Beard might have been caus’d by the shrinking or swelling of that part; but upon further examination, I found that the clefts, KK, LL, were stuft up with a kind of Spongie substance, which, for the most part, was very conspicuous neer the knee, as in the cleft KK, when the Beard was dry; upon the discovery of which, I began to think, that it was upon the swelling of this porous pith upon the access of moisture or water that the Beard, being made longer in the midst, was streightned, and by the shrinking or subsiding of the parts of that Spongie substance together, when the water or moisture was exhal’d or dried, the pith or middle parts growing shorter, the whole became twisted.

But this I cannot be positive in, for upon cutting the wreath’d part in many places transversly, I was not so well satisfy’d with the shape and manner of the pores of the pith; for looking on these transverse Sections with a very good Microscope, I found that the ends of [Schem. 15.]
Fig. 3. those transverse Sections appear’d much of the manner of the third Figure of the 15. scheme ABCFE, and the middle of pith CC, seem’d very full of pores indeed, but all of them seem’d to run the long-ways.