of the air by the sun and by their drying up as they get towards the pole and are borne away from it. And that thunderstorms are produced by heat falling upon the clouds. And that earthquakes come from the upper air falling upon that under the earth; for when this last is moved, the earth upheld by it is shaken. And that animals at the beginning were produced from water, but thereafter from one another, and that males are born when the seed secreted from the right parts of the body adheres to the right parts of the womb and females when the opposite occurs. He flourished in the 1st year of the 88th Olympiad, about which time they say Plato was born.[77] They say also that Anaxagoras came to have a knowledge of the future. 8. _About Archelaus._ Archelaus was of Athenian race and the son of Apollodorus. He like Anaxagoras asserted the mixed nature of matter and agreed with him as to the beginning of things. But he said that a certain mixture[78] was directly inherent in mind, and that the source of movement is the separation from one another of heat and cold and that the [Sidenote: p. 24.] heat is moved and the cold remains undisturbed. Also that water when heated flows to the middle of the universe wherein heated air and earth are produced, of which one is borne aloft while the other remains below. And that the earth remains fixed and exists because of this and abides in the middle of the universe, of which, so to speak, it forms no part and which is delivered from the conflagration.[79] The first result of which burning is the nature of the stars, the greatest whereof is the sun and the second the moon while of the others some are greater and some smaller. And he says that the heaven is arched over us[80] and has made the air transparent and the earth dry. For that at first it was a pool; since it was lofty at the horizon, but hollow in the middle. And he brings forward as a proof of this hollowness, that the sun does not rise and set at the same time for all parts as must happen if the earth were level. And as to animals, he says that the earth first became heated in the lower part when the hot and cold mingled and man[81] and the other animals appeared. And all things were unlike [Sidenote: p. 25.] one another and had the same diet, being nourished on mud. And this endured for a little, but at last generation from one another arose, and man became distinct from the other animals and set up chiefs, laws, arts, cities and the rest. And he says that mind is inborn in all animals alike. For that every body is supplied with[82] mind, some more slowly and some quicker than the others.