The Purist by Ogden Nash Lyrics

I give you now Professor Twist
A conscientious scientist
Trustees exclaimed, "He never bungles!"
And sent him off to distant jungles
Camped on a tropic riverside
One day he missed his loving bride
She had, the guide informed him later
Been eaten by an alligator
Professor Twist could not but smile
"You mean," he said, "a crocodile."