THREE:Mating, he thought. If the chain of obedience was broken would the trees refuse to obey, in their turn? Puna had said so, and it was true. And if the trees refused to obey there would be no mating...."I don't know anything about the different cars, my friend," said the Quartermaster haughtily. "That's the business of the railroad people. I simply order them to make up the trains for me, and they do the rest. There's a Yard-Master over there. Go ask him."