"Not all four!" interrupted Bart. "Fenn wasn't there. You see we were playing a joke on him," the lad went on, in a burst of confidence, realizing that it was useless to try to shoulder all the blame. "Ned, Frank and I came in here Friday night and got the things. I knew I had lost Ned's knife, but I didn't think I'd dropped it here. But Fenn wasn't along. We took the things to his house, and put them in the pen with his reptiles. He is making a collection."