Excitation of Nematocysts | Nature

ABSTRACT THERE has in the past been considerable discussion concerning the nature of the stimulus which causes the nematocysts of Cœlenterates to discharge, In some cases, it is quite clear

that the mechanical stimulus to the cnidoblast causes an, explosion of the enclosed nematocyst. But for the majority of nematocysts, discharge only takes place in the presence of food, and

it has been suggested that the stimulus is essentially a chemical one. During a long series of experiments on the feeding of _Anemonia sulcata_, interesting evidence has been obtained as to

the mode of excitation of nematocysts. In agreement with Parker and Van Alstyne1, I find the cnidoblasts of the tentacles of Anemonia are independent effectors. They respond, however,

selectively to food. If touched by a clean glass rod, no discharge is normally obtained. If touched with a piece of human skin, there is copious discharge. The discharge, however, only takes

place where there has been mechanical contact. Strong food solutions sometimes seem to cause spontaneous discharge of a few nematocysts. But it is easy to show that this is of no direct

significance in the normal reaction. As a direct chemical stimulus, food is far less effective than certain surface-active substances such as bile salts (0.1 per cent), which produce a

complete spontaneous discharge of the nematocysts. This action is, however, quite different from the normal response. Cotton wool soaked in dilute bile salts does not adhere to the tentacles

; the nematocysts being discharged, by the diffusing bile salt before contact is made. On the other hand, cotton wool soaked in food solution causes extensive discharge of nematocysts into

the mass on contact. This is true even though the food solution employed is far below the concentration for spontaneous discharge. Clean cotton wool, soaked in sea water as a control,

produces no discharge. Access through your institution Buy or subscribe This is a preview of subscription content, access via your institution ACCESS OPTIONS Access through your institution

Subscribe to this journal Receive 51 print issues and online access $199.00 per year only $3.90 per issue Learn more Buy this article * Purchase on SpringerLink * Instant access to full

article PDF Buy now Prices may be subject to local taxes which are calculated during checkout ADDITIONAL ACCESS OPTIONS: * Log in * Learn about institutional subscriptions * Read our FAQs *

Contact customer support SIMILAR CONTENT BEING VIEWED BY OTHERS NUMERICAL TESTS OF MAGNETORECEPTION MODELS ASSISTED WITH BEHAVIORAL EXPERIMENTS ON AMERICAN COCKROACHES Article Open access 09

June 2021 PIEZO ACTS IN AN INTESTINAL VALVE TO REGULATE SWALLOWING IN _C. ELEGANS_ Article Open access 21 November 2024 GUSTATORY FUNCTION OF SENSILLA CHAETICA ON THE LABIAL PALPS AND

ANTENNAE OF THREE TORTRICID MOTHS (LEPIDOPTERA: TORTRICIDAE) Article Open access 07 November 2022 REFERENCES * _J. Exp. Zool._, 63, 329 (1932). Download references AUTHOR INFORMATION AUTHORS

AND AFFILIATIONS * Department of Zoology, Cambridge C. F. A. PANTIN Authors * C. F. A. PANTIN View author publications You can also search for this author inPubMed Google Scholar RIGHTS AND

PERMISSIONS Reprints and permissions ABOUT THIS ARTICLE CITE THIS ARTICLE PANTIN, C. Excitation of Nematocysts. _Nature_ 149, 109 (1942). https://doi.org/10.1038/149109a0 Download citation

* Issue Date: 24 January 1942 * DOI: https://doi.org/10.1038/149109a0 SHARE THIS ARTICLE Anyone you share the following link with will be able to read this content: Get shareable link Sorry,

a shareable link is not currently available for this article. Copy to clipboard Provided by the Springer Nature SharedIt content-sharing initiative