Jellyfish canal. Cilia in these canals circulate the fluid in a regular direction. The box jellyfish is largely similar in structure. It has a squarish, box-like bell from each of the four lower corners of which hang a short pedalium or stalk which bears one or more long, slender tentacles. The rim of the bell is folded inwards to form a shelf known as a velarium which restricts the bell's aperture and creates a powerful jet when the bell pulsates, allowing box jellyfish to swim faster than true jellyfish. Hydrozoans are also similar, usually with just four tentacles at the edge
What Is This Thing Called Love? (short story) other, and wind up engaging in reproductive activities after all. What Is This Thing Called Love? (short story) "What Is This Thing Called Love?" is a science fiction short story by Isaac Asimov. The story was requested by Cele Goldsmith Lalli, editor of "Amazing Stories", as a satire of an article in "Playboy" called "Girls of the Slime God" which had suggested that pulp science fiction stories were concerned with aliens and sex. The story appeared in the March 1961 issue of "Amazing" as "Playboy and the Slime God", but Asimov later retitled it "What Is This Thing Called Love?"