Assertion: oyster's valve | /r/CapableOf | become defined on fourth day
Facets:
Source sentences:
text: On the first day the larvae develop into a blastulae (mass of cells with a center cavity), on day two they develop into a gastrulae (hollow two layered sac), on the third day they develop into trochophore (free-swimming, conciliated larvae), on the fourth day the valves on the dorsal surface become defined.