As it has no seas and no air, it follows that the moon has no sky. The lovely blue we see above us, is merely caused by many miles of air, but from the moon one would merely look away into immensity; and day, and night, sun, moon, stars, comets, and meteors could not be seen, while instead of the lovely blue dome above us, where stars innumerable shine and tremble, space, as seen from the moon, is a perpetual, limitless, black abyss. We have found the moon destitute of both air and water; it is evident that it is also destitute of all vegetation; in fact of all life. As there is darkness above, so there is silence below. The moon is a desert land where no foliage rustles, where no flowers bloom, where no bird builds or sings. No feet climb the lofty mountains, or explore the gaping craters of moon-land. No voice causes an echo in the vast yawning caves that penetrate moon-mountains. A curious fact about these mountains in the moon is that they are annular or ring-shaped. They are skeleton mountains, burnt-out craters, mighty hollow cones thrust up, so that if one might climb to the top of a moon-mountain, he could walk around the rim, as a fly walks around the edge of a cup; or he could go down, down, down, on the inside to the level of the plain from which he began his ascent. The surface of the moon changes, not by the motions of life and growth, but by a slow decay; for changes in the moon’s face are occasioned by the crumbling of mountains and the falling down of lands. Thus we see the moon to be a dumb, dead, deserted planet, wheeling on in its orbit around the earth, and carried with the earth in its greater orbit around the sun. Silvery sweet and fair, this queen of the night is a planet that long, long ago passed its childhood and its prime, and fell, in its old age, a prey to fire. LESSON XI. VANISHED FAUNA. “I said: ‘When first the world began Young Nature through five cycles ran, And on the sixth, she moulded--man.’” --TENNYSON, _The Two Voices_. The old fairy tales inform us of genii, and gnomes, and brownies that live underground, and in rocks and caves, guarding treasures of gold and of gems. Let us fancy that there are truly genii and gnomes that have lived from the time when life began until now. In every passing age each country has had its peculiar forms of animal life: these are called its fauna. The plant-life of an age or country is called its flora. As each age of earth-building came, it brought its especial fauna and flora. As the age passed away, this plant and animal life went away with it, and returned no more. But from every age some form or type has lingered until now. The pretty little lamp shells of the China seas come from the far-off second period of world-building. Some of these forms that have lived through all the ages have changed much to suit the conditions of new times; others have scarcely changed at all.