  We discuss some arguments in favour of the proposal that the quantum
correlations contained in the pure state-vector evolving according to
Schoedinger equation can be eliminated by the action of multiply connected
wormholes during measurement. We devise a procedure to obtain a proper master
equation which governes the changes of the reduced density matrix of matter
fields interacting with doubly connected wormholes. It is shown that this
master equation predicts an appropriate damping of the off-diagonal
correlations contained in the state vector.
