  We present empirical evidence of isospin dependence in the compound nuclear
fission cross-sections and fission widths, which suggests that the compound
nucleus (CN) possibly retains the memory of the isospin when it is formed. We
examine the idea, first proposed by Yadrovsky [1], for three pairs of reactions
where experimental data of fission cross section at various excitation energies
are available. One of the pairs of reactions is the same as used by Yadrovsky
i.e. $^{209}$Bi($p$, f) and $^{206}$Pb($\alpha$, f) leading to the CN
$^{210}$Po but with an improved experimental data set. The other two pairs of
reaction sets are, $^{185}$Re($p$, f) and $^{182}$W($\alpha$, f) leading to the
CN $^{186}$Os and, $^{205}$Tl($p$, f) and $^{202}$Hg($\alpha$, f) leading to
the CN $^{206}$Pb. An observable difference between the fission branching
ratios in two different isospin states suggests that the CN seems to remember
its isospin at the point of formation. This possibility is further supported by
another method, where additional empirical evidence for four CN, viz.
$^{210}$Po, $^{209}$Bi, $^{207}$Bi, and $^{198}$Hg, is obtained from the
experimental data in Zhukova et al. [2]. Further, the data also suggest a
possible new signature of the weakening of CN process and gradual transition to
non-compound processes as the energy rises. Fresh experimental efforts as
proposed, are required to confirm these findings.
