"As for the huge skull which Dr. Jamesson recovered. It is my opinion that the Jovians were not entirely immortal--that is, when they are outside of their accustomed atmospheric conditions. It is easy to believe that they achieved immortality on their own planet, for we today, on this globe, are slowly approaching a period when longevity will be increased to an astonishing degree. It is my prediction that we, too, will some day have achieved immortality to a certain degree inasmuch as radium is already known to have removed the cancerous tissues of the human anatomy that cause death. "However, I have reasons to believe that some of the Jovians were destroyed by the peculiar atmosphere of this earth when they arrived here. Naturally they could not be accustomed to our atmospheric conditions and results were that only the fittest survived the rigors of an alien planet. We must consider that years must have been consumed before they actually succeeded in locating the underground source of the radium deposit. Those who were unable to keep up the strenuous pace, weighted down by the earth's own atmosphere, were quite naturally cast aside. Some of them could not survive. Hence the skeletal remains recovered by Dr. Jamesson!" "But, Professor," I argued, seriously, "How could they survive the slugs from this gentleman's gun? Such a slug as shot from his calibre of gun would kill an elephant instantly." "That, my friend, is one of their secrets of immortality. I do not know how they could survive. I can merely hazard an opinion. This man narrated that a peculiar green liquid poured from the wounds. I am convinced, then, that a radium compound instead of blood, coursed through their veins with power enough to heal even the most gaping wounds instantly. Radium flowing through their anatomies would have the power to banish the leaden slugs even as they entered. The lead, like other lesser metals, would vanish into invisible atoms under the embrace of radium and would therefore have no more effect upon the Jovians than would pulverized dust. But great heat, alien atmospheric conditions or some tremendous violence, would actually destroy a Jovian if he were not of the most hardy sort. I feel certain of that, my friend!" * * * * * We remained all that day at the camp by the Mesquite Springs. After a hurried breakfast we lay down and slept until late afternoon. The heat was terrific and it beat down upon me with deadening effect. I slept through it, dreaming terrible dreams. Eventually I was awakened by Professor Bloch who had already prepared a light lunch. The mine-foreman was holding a pan of sizzling bacon over a tiny fire while the Professor set other victuals on the tail of the buckboard. I rubbed my eyes sleepily and tilted my hat forward to keep the burning sun from searing my face.