Ah. I misread the NewScientist article. It wasn't clear to me that in the experiment to mimic the slime they, in fact, modeled the slime with a circuit that _included_ a memristor and not with just a memristor. The paper the article cites also made things much clearer: http://fr.arxiv.org/abs/0810.4179
More technical: http://arstechnica.com/hardware/news/2009/01/logic-circuits-...