Authorities are not agreed concerning the causes that led to the extinction of the reptiles. Science still ponders over the mystery. A feature so extraordinary seems to demand an unusual explanation. Causes of a violent cataclysmic nature are advanced as valid interpretations. Yet science refuses to take cognizance of universal calamities and considers them as apocryphal because they are too unnatural. Climatic conditions, in the main, are probably responsible, for it is upon climate that the wealth or poverty of life on the globe depends. That which was a land of comfort, of abundant food, and of continual summer may have become, through a process of alternate haste and deliberation, a land of long winters, of bitterness and hardship. The good days of the world were exchanged for hard times, and those who could not survive were gathered to their forefathers. This, together with volcanic eruptions which took place on a stupendous scale, followed by glaciations of continental extent, apparently conspired in the ultimate undoing of reptilian life. These causes, in all likelihood, are responsible also for the shrinking of the majestic Sequoian woodlands to a mere fragment of their ancient, vast extent. About the end of the Miocene the earth became intensely active. In its agitation some of its seething interior was exuded to the surface in a deluge of lava. At the same time fountains of molten rocks shot up from volcanoes, causing the heavens to rain fire about them, and sifting ashes afar over the earth. Rivers and lakes floated up in immense clouds of steam over which the blazing beacons suffused weird colorings—lights and shades of an inferno that not even the pen of a Dante would have the temerity to attempt to describe. A land of beauty had become filled with forms of the gloomiest and ghostliest grandeur. The great _dinosaurs_ looked with disquietude upon it all. Unable, by reason of their cumbersomeness, to migrate to a gentler clime, they stoically awaited their doom. The _pterodactyls_, terrified, fluttered to the ground, flapping their great useless wings as the unearthly flashes from the heavens fell upon them. The noble Sequoias, even more impotent to make a retreat, held their ground until set afire or enveloped in floods of molten lava. At length, having exhausted its fury, this agent of wholesale ruin ceased as if stricken lifeless in the midst of its maddest rioting, and the land became a far-stretching waste out of which life had apparently gone forever.