Printed in Great Britain THE TRANSMISSION OF IMPULSES IN THE ECTODERMAL SLOW CONDUCTION SYSTEM OF THE SEA ANEMONE

1. The SSi fatigues in response to repetitive electrical stimulation. This fatigue is manifested by an increased conduction delay and a decreased SS1 pulse amplitude. 2. Continued repetitive stimulation leads to the failure of the system. Recovery may take many seconds. Narrow strips of column fail more rapidly than wide strips. 3. The increased conduction delay is explained in terms of a decrease in the population of spiking cells. 4. A computer model is described and analysed. It suggests that conduc-tion between electrically coupled ectoderm cells could be the basis for the SS 1. The SS 1 may have properties not so far experimentally demonstrated; for example, under certain conditions it could behave as a local system