mouth forms
... that the human mouth forms when the opening that becomes the anus tunnels through the embryo and comes out the other side?
... that the human <b id="mwEzE"><a href="./Embryological_origins_of_the_mouth_and_anus" id="mwEzI" rel="mw:WikiLink" title="Embryological origins of the mouth and anus">mouth forms</a></b> when the <a class="mw-redirect" href="./Blastopore" id="mwEzM" rel="mw:WikiLink" title="Blastopore">opening</a> that becomes the anus tunnels through the <a href="./Embryo" id="mwEzQ" rel="mw:WikiLink" title="Embryo">embryo</a> and comes out the other side?