In a central organizer model, signals from QC regulate stem cell behavior in all cells that contact it by means of a short range signal. In the dual axis model, opposing growth axes, which regulate each other’s division and differentiation gradients, displace their cells in opposite directions. Cells at the border of the opposing growth axes are not displaced by their neighbors whose daughters are pushed out of place in the opposite direction. These border cells behave as stem cells simply because they are not pushed away, a passive mechanism. Such a mechanism can result in bi-directional and radiating growth without a central organizer of division patterns.