Jacko, the monkey, was a source of great amusement, and greatly prized by young Buckland. "Once, when carrying him on a railway train, in a lawyer's blue bag," says Mr. Buckland, in his "Curiosities of Natural History," published some years afterwards, "Jacko, who must needs see everything that was going on, suddenly poked his head out of the bag, and gave a malicious grin at the ticket-giver. This much frightened the poor man, but, with great presence of mind, quite astonishing under the circumstances, he retaliated the insult, 'Sir, that's a dog; you must pay for it accordingly.' In vain was the monkey made to come out of the bag and exhibit his whole person; in vain were arguments in full accordance with the views of Cuvier and Owen urged eagerly, vehemently, and without hesitation (for the train was on the point of starting), to prove that the animal in question was not a dog, but a monkey. A dog it was in the peculiar views of the official, and three-and-sixpence was paid. "Thinking to carry the joke further (there were just a few minutes to spare), I took out from my pocket a live tortoise I happened to have with me, and, showing it, said, 'What must I pay for this, as you charge for _all_ animals?' The employé adjusted his specs, withdrew from the desk to consult with his superior; then returning, gave the verdict with a grave but determined manner, 'No charge for them, sir; them be insects.'" Whenever Jacko got loose, he found mischief. One day he covered a shoe, sole and all, with blacking, and poured what was left in the bottle inside the shoe. He also rubbed the white kitchen table all over with black-lead and water. Young Buckland spent his vacations at the University of Giessen, under the famous teacher and chemist, Professor Liebig, to whom he became greatly attached. "Returning in October, 1845, I brought with me," he says, "about a dozen green tree-frogs, which I had caught in the woods near the town.... I started at night on my homeward journey by the diligence, and I put the bottle containing the frogs into the pocket inside the diligence. My fellow-passengers were sleepy old smoke-dried Germans. Very little conversation took place, and, after the first mile, every one settled himself to sleep, and soon all were snoring. I suddenly awoke with a start, and found all the sleepers had been roused at the same moment. On their sleepy faces were depicted fear and anger. What had woke us all up so suddenly?