Cerianthus responds to a single condenser shock by a rapid contraction of tentacles and column. The response is symmetrical no matter where the shock is applied, from aboral end to tentacle tips, is propagated with a velocity of 1–2 m.sec., and is independent of the strength of the stimulus above threshold. The response is followed by an absolute refractory period of 60–70 m.sec. at 22–23° C. and a relative refractory period up to 200 m.sec. after the stimulus. For stimulation of either tentacles or column a threshold at twice the rheobase was obtained by discharge of a 0.05 µF. condenser through a total electrode-plus-preparation resistance of 3,000 ohms, thus giving a capacitance-resistance value of 0.15 m.sec. and chronaxie of 0.05 m.sec. Non-polarizable zinc–sulphate–zinc–agar glass tube electrodes of 0.5 mm. orifice diameter were used. With the same apparatus the chronaxie of the column through-conducting system of Naples specimens of Calliactis was 1.0 m.sec. Hill's1 equation for the excitation of nerve fits the strength-duration curve for Calliactis but does not approximate closely to that for Cerianthus. Complete curves of the strength-duration relation and the relative refractory period will be published elsewhere.
This is a preview of subscription content, access via your institution
Subscribe to this journal
Receive 51 print issues and online access
$199.00 per year
only $3.90 per issue
Rent or buy this article
Prices vary by article type
Prices may be subject to local taxes which are calculated during checkout
Hill, A. V., Proc. Roy. Soc., B, 119, 305 (1936).
Pantin, C. F. A., J. Exp. Biol., 12, 119 (1935).
Torelli, B., Pubbl. Stat. Zool. Nap., 23, 141 (1952).
About this article
Cite this article
HORRIDGE, G. Responses of Cerianthus to Stimulation. Nature 180, 1369–1370 (1957). https://doi.org/10.1038/1801369a0
This article is cited by
Zeitschrift f�r Zellforschung und Mikroskopische Anatomie (1973)