The squid and its giant nerve fibre.

Off the shore of Plymouth, the marine biology research ship, Sula, goes in search of squid. The narrator explains how the squid has significant scientific interest due to their similarities with vertebrates. Captive squid are seen in a tank. Meantimes, the fishermen sort the catch, putting the live squid into barrels. The special features of the squid are explained; it can expel a considerable amount of water in relation to its size - a captive specimen performs this feat. They have evolved a giant axon which allows them to propel themselves in a short burst of speed (the 'action potential'). Professor J. Z. Young dissects a squid in the laboratory and the nerves are visible to the naked eye. During his research in the 1930s, he discovered what initially looked to be a blood vessel, but turned out to be a nerve fibre, proven by electrical stimulation. Within the nerve fibre there is a giant axon, comprising of some of the largest known animal cells. Professor Baker recreates an experiment in the laboratory originally carried out by Alan Hodgkin and Andrew Huxley (who were Nobel prize winners for this work). There is a brief clip of Alan Hodgkin in the laboratory. Other laboratory experiments of a technical nature are performed. At the end, the scientists who participated in the laboratory recreations are listed as follows: Dr P. C. Caldwell, Sir Alan L. Hodgkin, Professor R.D Keynes, J. E. (John) Kimura, Dr P. McNaughton, Dr H. Meves, Professor T. I. Shaw, Professor J. Z. Young. Every winter the research laboratory fish for more squid to further their research.