Dear Bingley: In searching for etymology of "scytala" I found a French site that gives as third definition "a serpent".Perhaps from some snake that wraps itself about brances in climbing trees, or a constrictor?
"scytala, ae (scytale, es), f. : - 1 - bâton, rouleau. - 2 - scytale (rouleau entouré d'une bande de parchemin sur laquelle les Macédoniens écrivaient) - 3 - scytale (un serpent). "

Anyone who knows a little French will find this a fun place to browse. I've got to go back to get URL:
http://perso.wanadoo.fr/prima.elementa/Dico-s02.html

Interesting that it says it was used by Macedonians. They
might have gotten idea from Spartans, but it would no longer have been a secret.