The silt beds which Mr. Swift had selected were just deep enough to keep the plants from being discovered, yet enable them to receive sufficient sunlight.
Tom and his father started their planting. But no sooner had the first plants been embedded than fish darted in to nibble them. Even the roots disappeared into their greedy maws.
"Looks as though we'll have to build some sort of net enclosure around and over our farm," Mr. Swift said, after they had climbed back into the boat. "But at least your hydrolung device is a great success, son!"
Tom was thoughtful. "Dad, I wonder if the fish would eat those plants from space which you've been growing under salt water?"
Tom was referring to certain strange plants rocketed to earth by unknown space friends with whom the Swifts had been in communication.
"I have a hunch," Tom went on, "that the fish might be repelled by the unusual scent of those space plants. If so, we could scatter them among the earth plants to keep the fish away."
Mr. Swift was impressed by Tom's idea. As soon as they had returned to Enterprises, he proposed that the experiment get under way.
Tom volunteered to undertake the job at once with Bud. While the young inventor phoned his copilot, Mr. Swift went to his own laboratory to prepare the plants for shipment.
Twenty minutes later the boys took off in a jet. The plants had been parceled in transparent plastic film. Glistening with a red metallic sheen, they looked somewhat like tulips with honeycombed centers.
"Scarecrow plants to drive off fishes," Bud joked. "What will scientists think of next!"