"They and the Jeel cannibals, whom we are doing our best to exterminate," he replied. "You see, at one time, the dominant type of mobile land-life was the thing we call a shellosaur, a big thing, running from five to fifteen tons, plated all over with silicate shell, till it looked like a six-legged pine-cone. Some were herbivores and some were carnivores. There are a few left, in remote places--quite a few in the Southern Hemisphere, which we haven't explored very much. They were a satisfied life-form. Outside of a volcano or an earthquake or an avalanche, nothing could hurt a shellosaur but a bigger shellosaur. "Finally, of course, they grew beyond their sustenance-limit, but in the meantime, some of them began specializing on mobility instead of armor and began excreting waste-matter instead of turning it to shell. Some of these new species got rid of their shell entirely. _Parahomo sapiens Ulleris_ is descended from one of these. "The shellosaurs were still a serious menace, though. The ancestors of the present Ulleran, the proto-geeks, when they were at about the Java Ape-Man stage of development, took two divergent courses to escape the shellosaurs. Some of them took to the swamps, where the shellosaurs would sink if they tried to follow. Those savages, down there, are still living in the same manner; they never progressed. Others encountered problems of survival which had to be overcome by invention. They progressed to barbarism, like the people of the fishing-villages, and some of them progressed to civilization, like the Konkrookans and the Keegarkans. "Then, there were others who took to the high rocks, where the shellosaurs couldn't climb. The Jeels are the primitive, original example of that. Most of the North Uller civilizations developed from mountaineer-savages, and so did the Zirks and the other northern plains nomads." "Well, how about the Kragans?" Paula asked. "Which were they?" Von Schlichten was scanning the horizon ahead. He pulled over a pair of fifty-power binoculars on a swinging arm and put them where she could use them. "Right ahead, there; just a little to the left. See that brown-gray spot on the landward edge of the swamp? That's King Kankad's Town. It's been there for thousands of years, and it's always been Kankad's Town. You might say, even the same Kankad. The Kragan kings have always provided their own heirs, by self-fertilization. That's a complicated process, involving simultaneous male and female masturbation, but the offspring is an exact duplicate of the single parent. The present Kankad speaks of his heir as 'Little Me,' which is a fairly accurate way of putting it."