  Steady surface waves in a two-dimensional channel are considered. We study
bifurcations, which occur on a branch of Stokes water waves starting from a
uniform stream solution. Two types of bifurcations are considered: bifurcations
in the class of Stokes waves (Stokes bifurcation) and bifurcations in a class
of periodic waves with the period M times the period of the Stokes wave
(M-subharmonic bifurcation). If we consider the first Stokes bifurcation point
then there are no M-subharmonic bifurcations before this point and there exists
M-subharmonic bifurcation points after the first Stokes bifurcation for
sufficiently large M, which approach the Stokes bifurcation point when M tends
to infinity. Moreover the set of M- subharmonic bifurcating solutions is a
closed connected continuum. We give also a more detailed description of this
connected set in terms of the set of its limit points, which must contain
extreme waves, or overhanging waves, or solitary waves or waves with stagnation
on the bottom, or Stokes bifurcation points different from the initial one.
