Résumé
How does a biological system set up a body plan to produce a final organism with everything in the right place and orientation? I will discuss a developmental system (parhyale) that exploits activity and cell division to establish four-fold orientational order with the flexibility of a liquid but the structural rigidity arising from orientational order. Such ideas can be tested in active (self-propelled) Voronoi models of tissue that include cell division.
