  For conic bundles on a smooth variety (over a field of characteristic $\ne
2$) which degenerate into pairs of distinct lines over geometric points of a
smooth divisor, we prove a theorem which relates the Brauer class of the
non-degenerate conic on the complement of the divisor to the covering class
(Kummer class) of the 2-sheeted cover of the divisor defined by the degenerate
conic, via the Gysin homomorphism in etale cohomology. This theorem is the
algebro-geometric analogue of a topological result proved earlier.
