Time-lapse of stage 25 frontonasal mass dissected and cultured in control media. Nuclei were stained with Hoechst dye and imaged with confocal microscope, at 10X magnification (C1, control organ culture). Individual nuclei were tracked with manual tracking software. Dot is the end of the track and the tail is the trajectory of the movement. Cultures are oriented with the cranial edge uppermost in the image. The nasal slit is on the lateral sides of the tissue. The center of the frontonasal mass is relatively stationary in the center where cartilage will form at later stages.