Note Book IX. Chap. 1. Note (c) — BOOK IX.

[c] There is a great Deal of geometrical Neatness and Nicety, in the sinuous Motion of Snakes, and other Serpents. For the assisting in which Action, the annular Scales under their Body are very remarkable, lying cross the Belly, contrary to what those in the Back, and rest of the Body do; also as the Edges of the foremost Scales lye over the Edges of their following Scales, from Head to Tail; so those Edges run out a little beyond, or over their following Scales; so as that when each Scale is drawn back, or set a little upright by its Muscle, the outer Edge thereof, (or Foot it may be call’d,) is rais’d also a little from the Body, to lay hold on the Earth, and so promote and facilitate the Serpent’s Motion. This is what may be easily seen in the Slough, or Belly of the Serpent-kind. But there is another admirable Piece of Mechanism, that my Antipathy to those Animals hath prevented my prying into; and that is, that every Scale hath a distinct Muscle, one End of which is tack’d to the Middle of its Scale; the other, to the upper Edge of its following Scale. This Dr. Tyson found in the Rattle-Snake, and I doubt not is in the whole Tribe.