The Croonian Lecture - Ionic movements and electrical activity in giant nerve fibres

Abstract

During the course of an investigation into the central nervous systems of squids and cuttlefish, Professor J. Z. Young (1936 a , b ) noticed certain transparent tubular structures in the peripheral nerves. These must have seemed too large to be nerve fibres, and in a subsequent article Young (1944) remarked that he first took them to be blood vessels. However, on examining them more closely, he was able to prove that the tubes were, in fact, nerve fibres of exceptional size. Like many important discoveries, this was not an entirely new observation. It had been known since the time of Remak (1843) that Crustacea possessed giant nerve fibres, but with one exception the still larger fibres in cephalopods seem not to have been recognized as such. As Young pointed out, the exception was L. W. Williams who wrote a monograph on the squid which was published in 1909. In this monograph, Williams referred briefly to the large fibres in the nervous system. Williams did not commit himself as to the size of the fibres, but it is clear that he must have seen them. Thus he remarked that ‘The very size of the nerve processes has prevented their discovery, since it is well nigh impossible to believe that such a large structure can be a nerve fibre.’