  Based on the expectation that constituent quark model may capture right
physics in the large N limit, we point out that orbital angular momentum of the
quark-antiquark pair inside light mesons of low spins in the constituent quark
model may provide a clue for the holographic dual string model of large N QCD.
Our discussion, relying on a few suggestive assumptions, leads to a necessity
of world-sheet fermions in the bulk of dual strings that can incorporate
intrinsic spins of fundamental QCD degrees of freedom. We also comment on an
interesting issue of the size of mesons in the context of holographic QCD.
