  Experimental evidence for and against the existence of pentaquarks has
accumulated rapidly in the last three years. If they exist, they would be
dramatic examples of hadronic states beyond our well-tested and successful
particle models. The positive evidence suggests existence of baryonic objects
with widths of at most a few MeV, some displaying exotic quantum numbers, such
as baryons with strangeness $S = +1$. The non-observations of these states have
often come from reaction channels very different from the positive evidence
channels, making comparisons difficult. The situation has now been largely
clarified, however, by high-statistics repetitions of the positive sightings,
with the result that none of the positive sightings have been convincingly
reproduced. The most recent unconfirmed positive sightings suffer again from
low statistics and large backgrounds. It seems that a kind of ``bandwagon''
effect led to the overly-optimistic interpretation of numerous experiments in
the earlier reports of exotic pentaquarks.
