  Both the recently observed high runaway velocities of Cyg X-1 (~50 km/s) and
X-ray Nova Sco 1994 (> ~100 km/s) and the relatively low radial velocities of
the black hole X-ray binaries with low mass donor stars, can be explained by
symmetric mass ejection in the supernovae (SNe) which formed the black holes in
these systems.
  Assuming symmetric mass ejection in black hole formation, we estimate the
amount of mass that must have been ejected in the stellar core collapse in
order to explain the velocities of the above X-ray binaries. We find that at
least 2.6 M_sun and 4.1 M_sun must have been ejected in the formation of Cyg
X-1 and Nova Sco, respectively. A similar mass loss fraction (f = 0.35) for the
black hole binaries with low mass donors, gives low velocities, in agreement
with the observations.
  We conclude that the black holes in X-ray binaries are all consistent with
being formed in a successful SN in which mass is ejected. A possible kick at
the formation of the black hole is not needed to explain their space
velocities.
