A Mouthful

In 1854, a correspondent wrote to Notes and Queries asking about the origins of this couplet:

Perturbabantur Constantinopolitani
Innumerabilibus sollicitudinibus.

[“Constantinople is much perturbed.”]

He got this reply:

“When I first learned to scan verses, somewhere about thirty years ago, the lines produced by your correspondent P. were in every child’s mouth, with this story attached to them. It was said that Oxford had received from Cambridge the first line of the distich, with a challenge to produce a corresponding line consisting of two words only. To this challenge Oxford replied by sending back the second line, pointing out, at the same time, the false quantity in the word Constantinŏpolitani.”