The first terrestrial expedition to Mars didn't find any Martians. Neither did the second. Since there are so few Martians left, those facts are less surprising than that the third did. For many years before space flight was accomplished, there had been discussions and theories about how to communicate with Martians, if any existed. But, of course, nobody was ready when the time came. They fell back on that antiquated gimmick. Von Frisch, Riley and Smith watched the half dozen Martians approach,