Page:Anatomy of the Human Body (1918).djvu/57

Rh The Umbilical Cord and Body-stalk.—The umbilical cord (Fig. 28) attaches the fetus to the placenta; its length at full time, as a rule, is about equal to the <!--{{FIS|file=|width=|caption=Fig. 29.—Diagram of a transverse section, showing the mode of formation of the amnion in the chick. The amniotic folds have nearly united in the middle line. (From Quain's Anatomy.) Ectoderm, blue; mesoderm, red; entoderm and notochord, black.
 * <!--{{FIS|file=Fig. 30.—Fetua of about eight weeks, enclosed in the amnioa. Magnified a little over two diameters. (Drawn from stereoscopic photographs lent by Prof. A. Thomson, Oxford.)