The professor gave us a brief but modest account of his short tour of exploration. He had brought back a new species of orchid, several undescribed beetles, and a pocketful of coontie seed. He appeared, however, to be tired and singularly depressed, and presently we learned why. It seemed that he had gone straight to that section of the forest where he had hitherto always found signs of the transparent and invisible creatures which he had determined to capture, and he had not found a single trace of them. "It alarms me," he said, gravely. "If they have deserted this region, it might take a lifetime to locate them again in this wilderness." Then, very quietly, sinking her voice instinctively, as though the unseen might be at our very elbows listening, Miss Barrison recounted the curious adventure which had befallen the dog and the first batch of apple-pies. With visible and increasing excitement the professor listened until the very end. Then he struck the table with clinched fist--a resounding blow which set the concentrated soup dancing in the bowls and scattered the biscuits and the industrious red ants in every direction. "Eureka!" he whispered. "Miss Barrison, your deduction was not only perfectly reasonable, but brilliant. You are right; the pies are for that very purpose. I conceived the idea when I first came here. Again and again the pies that my guide made out of dried apples disappeared in a most astonishing and mysterious manner when left to cool. At length I determined to watch them every second; and did so, with the result that late one afternoon I was amazed to see a pie slowly rise from the table and move swiftly away through the air about four feet above the ground, finally disappearing into a tangle of jasmine and grape-vine. "The apparently automatic flight of that pie solved the problem; these transparent creatures cannot resist that delicacy. Therefore I decided to bait the cage for them this very night--Look! What's the matter with that dog?" The dog suddenly bounded into the air, alighted on all fours, ears, eyes, and muzzle concentrated on a point directly behind us. "Good gracious! The pies!" faltered Miss Barrison, half rising from her seat; but the dog rushed madly into her skirts, scrambling for protection, and she fell back almost into my arms. Clasping her tightly, I looked over my shoulder; the last pie was snatched from the table before my eyes and I saw it borne swiftly away by something unseen, straight into the deepening shadows of the forest. The professor was singularly calm, even slightly ironical, as he turned to me, saying: "Perhaps if you relinquish Miss Barrison she may be able to free herself from that dog." I did so immediately, and she deposited the cowering dog in my arms. Her face had suddenly become pink.