Diagram comparing the <a href="//commons.wikimedia.org/w/index.php?title=Embryology&amp;action=edit&amp;redlink=1" class="new" title="Embryology (page does not exist)">embryology</a> theories of <a href="//commons.wikimedia.org/wiki/Ernst_Haeckel" title="Ernst Haeckel">Ernst Haeckel</a> and <a href="//commons.wikimedia.org/w/index.php?title=Karl_Ernst_von_Baer&amp;action=edit&amp;redlink=1" class="new" title="Karl Ernst von Baer (page does not exist)">Karl Ernst von Baer</a>
<a href="//commons.wikimedia.org/wiki/User:Chiswick_Chap" title="User:Chiswick Chap">Ian Alexander</a>
CC BY-SA 4.0
<span class="int-own-work" lang="en">Own work</span>