It's probably a better idea to have your monkeys copy code trees around; i.e., rather than having (= monkey1!code "(+ x y)"), have (= monkey1!code (read "(+ x y)")), which is the same as (= monkey1!code '(+ x y)). A scheme like this (if you are careful about what you do with symbols) is a better idea because it's more Lisplike and you can thus take advantage of Lisp's strengths (list manipulation and code-is-data).
