Page:Life in Motion.djvu/173

Rh fitted up this beautiful experiment, as devised by Marey, to show you this. The pithed frog (entirely devoid of sensation) lies on this cork plate, and a thread from the tendon of

the gastrocnemius passes to a light lever writing on the surface of this drum. The cork plate, bearing the frog, is on a stand that moves by clockwork from left to right, so that the plate moves a little to the right during one revolution of the drum. Thus the tracings are kept from blurring, each successive curve being