Keywords: Life in Motion Fig 71.png en Fig 71 ”Diagram showing arrangement of apparatus used in demonstrating the action of light on the retina of a frog's eye A the eye having one electrode b touching the centre of the cornea and the other c touching the transverse section of the optic nerve; G galvanometer; D key The arrows show the direction of the current Life in Motion or Muscle and Nervehttps //archive org/details/b21929786 John Gray McKendrick 1892 1926 Life in Motion book Biology experiments |