Page:Philosophical Transactions - Volume 001.djvu/95

 forth, but growing white at last; having 24. feet, 8. on each side of the body, and 4. besides, close to each side of the head. During this form, they undergo constantly 4. Sicknesses, in which they cast their Skins, each sickness lasting about 4. days, wherein they feed not at all; but grow clearer, shorter, and thicker. The second; from a Worm to an Aurelia or Chrysalis, having the shape of a small Plum, whereunto it is transformed after its spinning time is past; in which state it lyes shut up, in hot Countries, for 14. or 15. dayes; in more temperate ones, 18. or 20. without any Food or Air, known to us. During which time this Insect leaves two Coats, both that of a Worm, whence 'tis changed into an Aurelia, and that of an Aurelia, whence it becomes a Papilio or Butterfly, in the Theca or Case. The third is, from Aurelia to a Butterfly coming out of the Theca with a head, leggs, and horns; for which passage it makes way by a whitish water, it casts upon the Silk, which moistning, and thereby in a manner putrefying it, the new creature thrusts out its head through the sharp end of the Case, by a Hole as big as its self. There is found no Excrement in the Case, but the two Skins onely, just now mentioned.

Before they begin to spin, and about the latter end of their feeding, they must, saith the Author, be often changed, and have Air enough, by opening the Windows of the Room, they are in, if it be not too ill Weather; else, saith he, the Silk that is in their Belly, will cause so extraordinary a heat in them, that it burns their gutts, and sometimes bursts them; and the same (being a substance that resembleth Gum or Burgundy Pitch) will putrefy and turn into a yellowish matter.

He maketh the best marks of their maturity for spinning to be, when they begin to quit their white Colour, and their green and yellow Circles, and grow of the Colour of Flesh, especially upon the tail; having a kind of a consistent sofenesssoftness [sic], shewing that they have something substantial in their Stomachs.

As for their Working, he gives this account of it, that the first day they make only a Webb; the second, they form in this Webb their Cases, and cover themselves all over with Silk; the third day, they are no longer seen, and the dayes following they thicken their Cases, alwayes by one end or thread, which they Rh