Ovariogram methodology. A. Ovariograms were constructed from the video micrographs as follows: a line was overlaid on the video image to cross the light/dark interface, in this case across the edge of the ovary. B. A plot of the change in position of the light dark boundary from frame to frame plotted (upper trace, 1 pixel is 1.7 μm) and of the mean square difference in intensity at each point along the line for successive pairs of frames (lower trace). The second method, recording the mean square difference in intensity provides a much greater sensitivity and also better discrimination of movement, as it takes into consideration the change in every pixel along the line, rather than just the position of the light/dark interface. Scalebar: 500 μm.