This is by Karen Weiss who says, “I was delighted to find your shaggy dog website and of course I can’t resist sending one of my own.”

A biologist specialised in amphibians. He was particularly interested in exploring the intelligence of these creatures and invented all sorts of tests to discover how well they could learn and remember. He found that a particular species of toad performed outstandingly in the tests and by a simple reward system with earthworms he taught one very bright toad, a toad genius he called Marmaduke, how to croak three times on command.

Thrilled at his success, he arranged to give a demonstration of his toad protege at the Royal Academy of Science. The big night came and while he was dressing to go, he asked his assistant to take Marmaduke and put him in a special traveling box, ready to take to the demonstration.

As the assistant was taking Marmaduke from his tank, he slipped in a puddle of water and fell on top of the talented toad, squashing him flat. In a panic, he grabbed another toad that looked exactly the same and shoved him into the traveling box and when the biologist asked for Marmaduke, he showed him the other toad.

Ignorant of the humiliation that awaited him, the biologist set off for London. At the Royal Academy, in front of some of the foremost minds in animal research, he spoke of his work at length and then finally brought out the toad for the demonstration. As he had done many times before, he wiggled an earthworm in front of the toad and gently tapped the table three times.

There was no response. Embarrassed, he tried again. Again, no success. He tried once more. The audience was starting to murmur. Frustrated, he picked up the toad to stroke its stomach, a trick that had often worked before. But as he did so, he noticed that the markings on the animal’s stomach were quite different to Marmaduke’s. With a howl of anguish, he held up the animal and yelled for all to hear, “It’s a wrong, wrong toad that has no learning!”