A method has been developed for the recording and analysis of low frequency movements such as those of the surfaces of live seminiferous tubules. The method involves time-lapse videomicrographic recording of the tubules followed by frame-by-frame measurement of the position of the edge of the tubule image in the video field. These measurements, which describe the movement of the tubule, may be analysed into a series of power spectra relating to sequential time periods through the recording. The group of spectrum plots for each tubule preparation can be plotted as isometric, pseudo three-dimensional figures, with time represented on the z-axis. The shapes of the spectra represent the contractile activity of the seminiferous tubules. Alterations in the level of activity and/or in the position of the frequency peaks, between control and experimentally treated preparations, are readily apparent. We also describe the construction and features of the perifusion chamber used with the VLMA.