World-Echinus

World-Echini (sing. "World-Echinus") is a nickname given to a species of planetary organisms that live amidst the ether in space, orbiting stars such as Sol. Their existence was originally proposed by Prof. George Edward Challenger, who demonstrated that the planet Earth is actually a living creature resembling a giant spaceborne sea-urchin, and postulated that the same must be true for Venus, Mars and others. Prior to Challenger's drilling experiment at Hengist Down, Sussex, other Humans were very skeptical of his claims.

Biology
Very little is known about the biology of a World-Echinus, although Prof. Challenger is convinced that it possesses circulatory, respiratory and nervous systems; that its overall anatomy is similar to that of a common echinus, a.k.a. sea urchin; and that it feeds by absorbing particles from the ether.

Although its metabolism is extremely slow, its breathing may be perceptible as "the secular rise and fall of land", as Challenger put it, and the phenomenon that Humans perceive as earthquakes may be more akin to "fidgetings and scratchings" of its humongous musculature. Volcanoes, meanwhile, represent heat spots.

Beneath a roughly 8-miles-thick crust (~ 12.9 km), the flesh of the World-Echinus has a gelatinous consistency, greyish and translucent, dotted with bubbling vacuoles. When this flesh was perforated in Challenger's experiment, an extremely loud howling shriek was heard. The sound was louder at the actual site of penetration, but was also heard coming from every vent and volcano of the planet. The Echinus also spilled out a dark, foul-smelling tar-like fluid which rained unpleasantly on those gathered to watch the experiment.

Appearances

 * "When the World Screamed", by Sir Arthur Conan Doyle (1928)