  Within the framework of a simple Rouse-type model we present exact analytical
results for dynamical critical behaviour on the sol side of the gelation
transition. The stress-relaxation function is shown to exhibit a
stretched-exponential long-time decay. The divergence of the static shear
viscosity is governed by the critical exponent $k=\phi -\beta$, where $\phi$ is
the (first) crossover exponent of random resistor networks, and $\beta$ is the
critical exponent for the gel fraction. We also derive new results on the
behaviour of normal stress coefficients.
