'Yolk cord' definitions:

Definition of 'Yolk cord'

From: GCIDE
  • Yolk \Yolk\ (y[=o]lk or y[=o]k; 277), n. [OE. yolke, yelke, [yogh]olke, [yogh]elke, AS. geoloca, geoleca, fr. geolu yellow. See Yellow.] [Written also yelk.] [1913 Webster]
  • 1. The yellow part of an egg; the vitellus. [1913 Webster]
  • 2. (Zool.) An oily secretion which naturally covers the wool of sheep. [1913 Webster]
  • Yolk cord (Zool.), a slender cord or duct which connects the yolk glands with the egg chambers in certain insects, as in the aphids.
  • Yolk gland (Zool.), 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. [1913 Webster]