National Geographic : 1926 Aug
Photograph from Charles Frederick Holder A GIANT JELLYFISH Some of these marine creatures have tentacles many feet in length. Jellyfishes are best known tosalt-water bathers as "sea-nettles." They sting their victims by means of a tiny mechanism attached to the tentacles and consisting of a sac containing anirritant poison. Within this iscoiled a slender, threadlike tube, sometimes barbed. A microscopic "trigger" hair projects from the outer surface ofthe sac, and when touched discharges the tube, which has a considerable power of penetration. The result is much as if the poison had been injected into the body with aminiature hypodermic and produces a burning sensation on the skin.