We numerically study the bifurcations of two nonlinear maps, with the
same linear part, which depend on a parameter namely the Henon quadrat
ic map and the so called 'beam-beam' map. Many families of periodic or
bits which bifurcate from the central family, are studied. Each family
undergoes a sequence of period doubling bifurcations in the quadratic
map. But the behavior of the 'beam-beam' map is completely different.
Inverse bifurcations occur in both maps. But some families of the sam
e type which bifurcate inversely in the quadratic map do not bifurcate
inversely in the 'beam-beam' map, even though both maps have common l
inear part.