Zor Ala nodded. "Even in my time we still didn't know," he said. "We had theories that perhaps the tiny mammals of the later Mesozoic were eating the eggs of the dinosaurs to an extent which brought about their eventual extinction. There was also the theory of 'dilution of genetic stock' in a very old race of any life form. That is, through millions of years of reproduction, the hereditary stock of any race eventually becomes so diluted that the cells become 'tired' of dividing. As a result, reproduction dwindles away, and the race dies out. But even that doesn't satisfactorily explain the geologically sudden death of the dinosaurs." "Apparently quite a parallel to what must have happened to the Kralons," Malherne observed. "How is it that we don't find clear paleontological evidence of the existence of the Kralons?" "No calcareous skeletal structure," returned Zor Ala. "They have only a chitinous exoskeleton. Also, you must remember that the dinosaurs held sway for almost 100 million years, and invaded almost every part of the world. In all that time, with the animals existing by the billions in almost every clime, there were naturally a few 'saurs' who fell into asphalt pits or other unusual environments where their bones were preserved for us. "That is not true of the Kralons, for they seem to have suddenly appeared as the first insect type, sometime during the latter half of the Carboniferous Period, and existed as a race for only a few million years. "Furthermore, their distribution is apparently very limited. From what they have told me, there are only a few dozen community hives or nations like this one. Thus it is not at all surprising that such an extremely restricted species, possessing no calceous skeletal structure, left no paleontological evidence." Malherne considered this thoughtfully. "Then you believe that the insect types of the future are degenerated descendants of the Kralons?" he asked. "Undoubtedly," returned Zor Ala. "But without the size or the logical reasoning ability of the Kralons. You see, insects apparently arose suddenly during the Carboniferous Period, without any prior evidence of existence in the ages preceding. They seem to be an offshoot from the main line of evolutionary development, and their sudden appearance in geologic history is without precedence in the development of life forms." Malherne was nodding eagerly. "In connection with that, why is it that an insect goes along in its development, just like a common worm, until it reaches a certain size and age. Then it builds itself a cocoon or chrysalis, becomes a pupa, and starts a sort of 'prenatal' development all over again, but this time emerging as a full-fledged insect? Seems like they've been given a second crack at development which the other forms of life didn't get."