In his column on this topic, http://www.straightdope.com/classics/a5_266.html, Cecil quotes Lewis Carroll as saying “it is never put with the wrong end in front.”
This is a misquote, caused by an overzealous copy editor. The original note said “it is nevar put with the wrong end in front.”
Perhaps you should re-read what Cecil wrote.
"Postscript: In 1976 Carroll admirer Denis Crutch pointed out that in the 1896 preface quoted above, the author had originally written: “It is nevar put with the wrong end in front.” Nevar of course is raven spelled backward. Big joke! "
Here’s an additional explanation that I once read in an article in a very old edition of M.L.A. (while working on an english paper about the nonsense in Alice in Wonderland). A raven eats worms and a writing desk is eaten by worms. (Often, writing desks were made of wormwood in the time of Lewis Carrol).
Of course, this is also probably just an afterthought. As Cecil points out, the riddle is not meant to have a sensical answer.
My favourite answer has always been “because there is a B in both”. I’d not seen the “and an N in neither” extension until Cecii’s column. Cool.
Meanwhile, welcome to the Straight Dope Message Boards, gopi!
I always thought it was because Poe wrote upon both of them.
Maybe it’s just me, but I always thought it was either a thought-provoking, rhetorical riddle, or simply one with no answer designed to confuse Alice.
It’d be helpful if you’d read the column before commenting. You’d find your answer, there, Lady Eboshi, and you’d find your comment there, Avarice.