1574 J. Jones 26 Termed in Greeke..Chorion, Secundina of the Latines, of most in English, the Sely how.
1616 A. Roberts 66 That naturall couer where with some children are borne, and is called by our women, the sillie how.
1648 G. Daniel ii. 25 May wee not pull The Syllie-Hoe..Away? but tarrie Infants, in the wombe Of Ignorance.
1710 T. Ruddiman in G. Douglas tr. Virgil (new ed.) Gloss. at How In Scotland the women call a haly or sely How..a film or membrane stretched over the heads of Children new born.
1777 J. Brand App. 367 Various were the Superstitions, about half a Century ago, concerning a certain membranous Covering, commonly called the Silly How, that was sometimes found about the Heads of new-born Infants.
a1866 W. Anderson (1867) 67 (note) Anyone possessing a Seelyhoo' legally is always progressing in fortune.
1894 R. O. Heslop (at cited word) The silly-hue is usually preserved, and is believed to sympathise with the person whose face it covered.
1922 38 85 The use of an animal's caul as an amulet is unusual, but a child's caul or ‘silly-how’, as it is sometimes termed, was at one time considered a very valuable possession.
1971 K. Thomas vii. 188 Along with them went the belief that the infant's expectation of life could be divined from a scrutiny of the after-birth, or that good fortune would accompany the child born with the caul (or ‘sillyhow’) over its head.
2006 21 Dec. 80/1 The sillyhow (literally a happy hood) of the poem's title is another word for a caul.