As yet the surrounding mesenchyme shows little change beyond a moderate cellular proliferation. caudal to the stalk of the umbilical vesicle the intestine is less advanced, thereby participating in the rostrocaudal gradient of differentiation that characterizes the embryo as a whole.

Based on Born reconstructions of No. 836, made by Osborne O. Heard under the supervision of H.M. Evans..

[Adapted from figure 13-9]

[Text and figure from O'Rhailly, R., and Müller, F.. Developmental Stages in Human Embryos, Carnegie Institution of Washington, Publication 637, 1987.]