  We continue and extend earlier work on the summation of planar graphs in
phi^3 field theory, based on a local action on the world sheet. The present
work employs a somewhat different version of the self consistent field
(meanfield) approximation compared to the previous work on the same subject.
Using this new approach, we are able to determine in general the asymptotic
forms of the solutions, and in the case of one solution, even its exact form.
This solution leads to formation of an unstable string, in agreement with the
previous work. We also investigate and clarify questions related to Lorentz
invariance and the renormalization of the solution.
