It seems anatomically true that if we cut off the end of a male, a female might result. This is supported by folklore, in which boys are made from sticks and snails and puppy dog's tails, which we can cut off (with a carving knife?). Everyone knows of Norma(n), Fran(k), Olive(r) and Julia(n): here are many names that could belong to boys, which, upon losing a single letter, produce a name that could belong to a girl!
"The Unkindest Cut,"
Word Ways: Vol. 33
, Article 12.
Available at: http://digitalcommons.butler.edu/wordways/vol33/iss1/12