For many minutes the amazing shape of twisting green radiance hung in the air. Sam was busy with his apparatus, squinting at the thing through telescope and spectroscope, and reading his other devices. At last the awful, throbbing thing faded away, and died into nothingness. Only the violet lances were left in the mist. "Many of my theories were substantiated," Sam informed me, almost jubilant. "And I got a lot of new data! It is rather odd, but the light from that thing shows the helium lines as luminous bands, not as the dark lines that might be expected to rise from the absorption of the helium in this atmosphere! I can hardly understand it!" He said nothing more, but was sunk deep in thought as we quickly gathered the instruments and hastened silently down the hill. I felt that he had won a notable victory in the invention of the thought-insulating helmets. We arrived at the machine again without accident. CHAPTER XXII The Silver Sphere For several days longer, Sam continued his labors in the laboratory. During that time "Alexander," the flying plant, developed remarkably. Before we moved, it had a wing-spread of two or three feet. I have spoken of its intelligence. It soon learned to flutter to the guns when we were preparing to hunt. Sam talked to it incessantly, and declared that it could understand him. He said it could even make its thoughts known by the varying pattern of colors on its fringe of brilliant membrane. Presently he had it trained to dry dishes and to do other similar tasks in the galley. Of course the thing never learned to speak. In fact, it was devoid of vocal organs, and incapable of making a sound, though its hearing seemed to be good enough. It appeared to communicate its emotions and thoughts by means of changes of color in the tissue-like membrane that I have termed a flower. And, from a strictly scientific point of view, communication by light, or sight, is quite as logical as communication by sound. Sam examined the black, rod-like organs projecting from the flower on the thing, and said that each of them bore thousands of tiny eyes, like the compound eyes of an insect. After we had been in the vicinity for perhaps two weeks by upper world time, we started the Omnimobile's great motors again, and moved northward. I had not told Xenora about my talk with Sam--our minds were too closely attuned to require much conversation. I knew that she understood that our maneuver would probably mean our sacrifice to the cause of the world. She said nothing of it, but I thought I detected a sadness in her manner.