Aside from the question of the control of human destiny by the constellations at birth, Pliny’s general theories of the universe and of the influence of the stars upon terrestrial nature are roughly similar to those of astrology. For him the universe itself is God, “holy, eternal, vast, all in all, nay, in truth itself all;”[456] and the sun is the mind and soul of the whole world and the chief governor of nature.[457] The planets affect one another. A cold star renders another approaching it pale; a hot star causes its neighbor to redden; a windy planet gives those near it a lowering appearance.[458] At certain points in their orbits the planets are deflected from their regular course by the rays of the sun,—an unwitting concession to heliocentric theory.[459] Pliny ascribes the usual astrological qualities to the planets.[460] Saturn is cold and rigid; Mars, a flaming fire; Jupiter, located between them, is temperate and salubrious. Besides their effects upon one another, the planets especially influence the earth.[461] Venus, for instance, rules the process of generation in all terrestrial beings.[462] Following the _Georgics_ of Vergil somewhat, Pliny asserts that the stars give indubitable signs of the weather and expounds the utility of the constellations to farmers.[463] He tells how Democritus by his knowledge of astronomy was able to corner the olive crop and put to shame business men who had been decrying philosophy;[464] and how on another occasion he gave his brother timely warning of an impending storm.[465] But Pliny does not accept all the theories of the astrologers as to control of the stars over terrestrial nature. He repeats, but without definitely accepting it, the ascription by the Babylonians of earthquakes to three of the planets in particular,[466] and the notion that the gem _sandastros_ or _garamantica_, employed by Chaldeans in their ceremonies, is intimately connected with the stars.[467] He is openly incredulous about the gem _glossopetra_, shaped like a human tongue and supposed to fall from the sky during an eclipse of the moon and to be invaluable in selenomancy.[468] [Sidenote: Astrological medicine.]