A pair of connected Madin-Darby bovine kidney epithelial cells undergo mitosis almost simultaneously, quickly forming a small colony. Both of the original cells retract their surface extensions prior to the process and assume roughly spherical geometries. The daughter cells settle on the substratum soon after they are produced. Lamellipodia are notably only extended along their free margins.

Another MDBK cell colony is located in the lower right-hand corner of the field of view. Most of the cells in the colony actively migrate as group toward the right, but a seemingly adventurous cell successfully breaks away. The incentive for the cell’s declaration of independence appears to be a few cytoplasmic fragments scattered across the substratum, which were just out of the reach of its extended lamellipodia when the cell was connected to the colony.

The cells of the opposing colony also attempt to reach the cytoplasmic debris sought by the recently freed migrating cell. Unhindered by neighboring cells, the individual cell is able to reach the prize much more rapidly than the small colony of cells and quickly incorporates the material into its own contents. Subsequently, the cell collides with the oncoming colony, and despite a flurry lamellipodial activity, its further individual migration is inhibited. Instead, the cell becomes another member of the growing colony, which commences locomotion toward the right of the field of view.