We report on a measurement of the mean charged-particle multiplicity of jet
s in dijet events with dijet masses in the range 80-630 GeV/c(2), produced
at the Tevatron in p(p) over bar collisions with roots = 1.8 TeV and record
ed by the Collider Detector at Fermilab. The data are fit to perturbative-Q
CD calculations carried out in the framework of the modified leading log ap
proximation and the hypothesis of local parton-hadron duality. The fit yiel
ds values for two parameters in that framework: the ratio of parton multipl
icities in gluon and quark jets, r = N-partons(g-jet)/N-partons(q-jet) = 1.
7 +/- 0.3, and the ratio of the number of charged hadrons to the number of
partons in a jet, K-LPHD(charged) = N-hadrons(charged)/N-partons = 0.57 +/-