Conundrums have been a popular form of word puzzle for well over a century. One form of conundrum appeals especially to the logologist: the one that asks why a specified letter of the alphabet has a certain characteristic. It comes int two varieties according to the form of the answer; in one, the answer depends on the existence of a certain letter in a word, and in the other, the answer depends on the deletion of a letter from a word, forming a new world. In general, the second is more difficult to construct than the first.
Eckler, A. Ross
"The Letter Conundrum,"
Word Ways: Vol. 24
, Article 9.
Available at: https://digitalcommons.butler.edu/wordways/vol24/iss1/9