  We report new precise p$(\vec{e},e^\prime p)\pi^0$ measurements at the peak
of the $\Delta^{+}(1232)$ resonance at $Q^2=\unit[0.20](GeV/c)^2$ performed at
the Mainz Microtron (MAMI). The new data are sensitive to both the electric
quadrupole ($E2$) and the coulomb quadrupole ($C2$) amplitudes of the $\gamma^*
N\to\Delta$ transition. They yield precise quadrupole to dipole amplitude
ratios CMR $= (-5.09 \pm 0.28_{stat+sys}\pm 0.30_{model})%$ and EMR $= (-1.96
\pm 0.68_{stat+sys} \pm 0.41_{model})%$ for $M^{3/2}_{1+} = (39.57 \pm
0.75_{stat+sys}\pm 0.40_{model})(10^{-3}/m_{\pi^+})$. The new results are in
disagreement with Constituent Quark Model predictions and in qualitative
agreement with models that account for mesonic contributions, including recent
Lattice calculations. They thus give further credence to the conjecture of
deformation in hadronic systems favoring the attribution of the origin of
deformation to the dominance of mesonic effects.
