Description: Segment 1 Huxley sums up the conclusions from the first lecture and continues to discuss electrical conduction in relation to muscle fibres. Time start: 00:00:00:00 Time end: 00:04:44:13 Length: 00:04:44:13 Segment 2 Referring to a diagram, Huxley discusses an experiment on a striated muscle fibre from a frog's leg. A short film sequence is shown in which Huxley shows a twitch fibre from the skeletal muscle of a frog being stimulated. The images shown are made by a polarising microscope. Time start: 00:04:44:13 Time end: 00:09:59:14 Length: 00:05:15:01 Segment 3 Huxley shows a series of electron micrographs of frog muscle, more or less stimulated. Time start: 00:09:59:14 Time end: 00:15:06:20 Length: 00:05:12:06 Segment 4 Huxley shows further electron micrographs of experiments on frog muscle fibres and explains the processes used by other researchers in the field. Time start: 00:15:06:20 Time end: 00:19:32:20 Length: 00:04:26:00