“Yes, yes. During the Age of Chalk, nearly all Europe was under a warm sea. There were millions of little sea-creatures with shells, in those tepid waters. Sea-shells, you know, are made out of the lime that is dissolved in the sea, but after that lime has been made into a sea-shell it does not dissolve. These billions of microscopic shellfish lived, made their homes and died, so that their shells rained continually through the water to the ocean floor, and, inch by inch, the accumulated shells made deep beds of lime or chalk. Some beds are hundreds of feet thick. “Slowly, slowly, the bed of the ocean rose, until it came near the surface of the sea. Still it rose, throwing off the water that had covered it. The oceans rushed into a new bed, and Western America, Southern Europe and Southern Asia rose above the water for the last time, much in their present outlines. “The changes of the earth’s crust made numberless volcanoes, especially in those parts of the earth that had just appeared above the surface. In the glare of eruptions that never stopped, amid the thunder of vast explosions, the hissing of great geysers and the unceasing growl of earthquakes, the land grew higher and higher above the sea, and the world grew colder and colder. It was the end of the Empire of Reptiles.” “Ah!” exclaimed Perry, remembering his dream. “As the world grew colder,” Antoine continued, “the soft vegetation died away and harder grasses and trees and shrubs took its place, needing creatures with better teeth to chew the stronger fibers. And still the grip of the cold increased. “In that time of miserable frigidity, the flying lizards suffered terribly. Their thin wings of membrane had no resistance to the biting blasts that whistled over the ever-rising land. Their cold blood afforded no store of vitality against the frost. “The birds, their rivals, protected with feathers, with warm blood in their veins, with deep breastbones giving them muscles enabling them to fly long distances, got the pick of the food. One by one the shivering pterodactyls disappeared, and perhaps the great specimen of Pteranodon in our Museum was the very last of the giant flying reptiles. “We can almost see him, half-starved, half-frozen, gliding over the waters of the sea, his gaunt ungainly frame growing weaker and more feeble as numbness stole over him, only, at last, to fall into the ocean that once flowed over what is now the State of Kansas. And so he died, the great Pteranodon, the last of his kind, and, for size, the crested monarch of all that flew in any age that had been or was to come.” CHAPTER IV SEEING THE SEA-SERPENT For the next two days Perry was kept busily at work on his examinations, for, as his father had suggested, it was on ship-board that the boy’s uncle felt the time to be most opportune for getting that work done. He was deep in one of his examination papers, when, suddenly, his uncle called to him: “Here’s a sea-serpent, Perry!”