Figure 2.

Outer morphology of a Carnegie-stage 10 human embryo as depicted by a historical three-dimensional model manufactured in the studio of Friedrich Ziegler in Freiburg/Breisgau, Germany. This embryo was described, for the first time, by the Swiss anatomist Auguste-Francois-Charles de’Eternod in 1896 and 1899 [17,18]. Pictures of this embryo or its heart were published in many textbooks, atlases and articles on human embryology during the 20th century. The embryo had a greatest length of 2.11 mm and seven pairs of complete somites + one pair of incomplete somites. The model is shown in right ventral (A), ventral (B), left ventral (C), right lateral (D), dorsal (E), and left lateral (F) views. Abbreviations: AIP = anterior intestinal portal; CS = connecting stalk; H = bulge of the body wall produced by the heart and pericardial cavity; NA = neuroporus anterior; NP = neuroporus posterior.