Category:Yolk

Yolk, n. Etym: [oe. yolke, yelke, ýolke, ýelke, as. geoloca, geoleca, Fr. geolu yellow. See yellow.] [written also yelk.]

1. The yellow part of an egg; the vitellus.

2. (zoöl.)

Defn: an oily secretion which naturally covers the wool of sheep. Yolk cord (zoöl.), a slender cord or duct which connects the yolk Glands with the egg chambers in certain insects, as in the aphids. -- yolk gland (zoöl.), a special organ which secretes the yolk of The eggs in many turbellarians, and in some other invertebrates. See Illust. of hermaphrodite in appendix. -- yolk sack (anat.), the umbilical vesicle. See under unbilical.