  In hadron induced air showers of highest energies (E> 1e18 eV), the lateral
distribution functions of electrons and muons are a superposition of many
separate electromagnetic sub-showers, initiated by meson decay at different
altitudes and energies. The lateral distribution function is the primary tool
for reconstructing the energy of the primary in a UHE cosmic ray shower, so
understanding it in detail is a prerequisite for having confidence in the
energy determination. We analyze in this paper the dominant contributions to
the ground level lateral distribution functions, as a function of the altitude
and energy at which the sub-showers are initiated. Far from the core, the
dominant contribution to the density of electrons comes from sub-showers
initiated at low altitudes and low energies (E<100 GeV). The dominant
sub-showers are initiated at large radial distance from the core and at a large
angle with respect to the main shower axis. This demonstrates the need for
careful treatment of low energy hadron physics modeling even for ultrahigh
energy primaries.
