cardiac jelly

n.

The gelatinous noncellular material between the endothelial lining and the myocardial layer of the heart in very young embryos, later serving as a substratum for cardiac mesenchyme.

The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.