  We present a detailed analysis of the use of heavy quark fragmentation into
heavy hadrons for testing the heavy quark effective theory through comparison
of the measured fragmentation parameters of the $c$ and $b$ quarks. Our
analysis is entirely model independent. We interpret the known perturbative
evolution in a way useful for exploiting heavy quark symmetry at low energy. We
first show consistency with perturbative QCD scaling for measurements done
solely with $c$ quarks. We then apply the perturbative analysis and the heavy
quark expansion to relate measurements from ARGUS and LEP. We place bounds on a
nonperturbative quark mass suppressed parameter, and compare the values for the
$b$ and $c$ quarks. We find consistency with the heavy quark expansion but
fairly sizable QCD uncertainties. We also suggest that one might reduce the
systematic uncertainty in the result by not extrapolating to low $z$.
