[Foucault-L] Foucault on Diagram as a place of Mutation

Deleuze, on his book for Foucault, claims that "...the diagram, in so far as it exposes a set of relations between forces, is not a place but rather "a non-place": it is the place only of mutation...."
My question is, where can i find more reasoning in Foucault about mutation -which book, chapter, etc.?
Discover the new Windows Vista
Partial thread listing: