  We study the distribution function of the three dimensional wormlike chain
with a fixed orientation of one chain end using the exact representation of the
distribution function in terms of the Green's function of the quantum rigid
rotator in a homogeneous external field. The transverse 1d distribution
function of the free chain end displays a bimodal shape in the intermediate
range of the chain lengths ($1.3L_{p},...,3.5L_{p}$). We present also
analytical results for short and long chains, which are in complete agreement
with the results of previous studies obtained using different methods.
