A centipede was happy - quite!
Until a toad in fun
Said, 'Pray, which leg moves after which?'
This raised her doubts to such a pitch,
...
George William Humphrey (17 July 1889 – 24 April 1966) was a British psychologist, author, and philosopher. He is the founder of the Canadian Psychological Association. He was the first Director of the Institute of Experimental Psychology and Professor of Psychology at the University of Oxford. Humphrey’s research concentrated on behavioral studies such as reinforcement, habituation, and apparent movements, as well as psychophysical topics like audiogenic seizures. He is known for Humphrey’s Law.)
The Centipede's Dilemma
A centipede was happy - quite!
Until a toad in fun
Said, 'Pray, which leg moves after which?'
This raised her doubts to such a pitch,
She fell exhausted in the ditch
Not knowing how to run.