Nadia found this interesting. “Look,” she said to Arne, “what about a pedon filled with a matrix of feeder veins, which would introduce the biota all through the parent material.” Take a batch of parent material, she went on, and get it wet, then let it dry. Insert into the crack systems the feeder vein matrix. Then pour in whatever important bacteria and other constitutents they could grow. Then if the bacteria and other creatures could eat their way out of their feeder veins, digesting that material as they emerged, they would all suddenly be there together in the clay, interacting. That would be a tricky time, no doubt many trials would be necessary to calibrate the initial amounts of the various biota needed to avoid population booms and crashes— but if they could get them to settle into their usual communities, then they would suddenly have living soil. “There are feeder-vein systems like this used for certain quick-setting construction materials, and now I hear that doctors feed apatite paste into broken bones the same way. The feeder veins are made of protein gels appropriate to whatever substance they’re going to contain, molded into the appropriate tubular structures.”

A matrix for growth. Worth looking into, Arne said. Which made Nadia smile. She went around that afternoon feeling happy, and that evening when she joined Art she said, “Hey! I did some work today.”

“Well!” Art said. “Let’s go out and celebrate.”

• • •