  New molecular line observations of the Bok globule Barnard 68 in HCO+
irrefutably confirm the complex pattern of red and blue asymmetric line
profiles seen across the face of the cloud in previous observations of CS. The
new observations thus strengthen the previous interpretation that Barnard 68 is
undergoing peculiar oscillations. Furthermore, the physical chemistry of B68
indicates that the object is much older than the sound crossing time and is
therefore long-lived. A model is presented for the globule in which a modest
external pressure perturbation is shown to lead to oscillations about a stable
equilibrium configuration. Such oscillations may be present in other stable
starless cores as manifested by a similar signature of inward and outward
motions.
