Elastic c~-scattering angular distributions have been measured at E~=36.2MeV, 39.6MeV, 42.6MeV, 49.5MeV, 61.0MeV for 4~ and at E~=36.2MeV, 42.6MeV, 49.5 MeV and 61.0 MeV for 44Ca, respectively. At backward angles the data display an oscillatory structure for E~<50MeV and more smoothly decreasing slopes at E~ =61.0MeV resembling the data obtained at higher energies. The 4~ data below E~ =50MeV show the well known backward enhancement, which at 42.6MeV and 49.5 MeV can be fitted by a p2 and a P~ respectively. Together with previous data, p2_ structures have now been observed for all L-values between L= 8 and L= 16. The slope of the curve L(L + 1) versus excitation energy is slightly smaller for L > 12 than for L < 12. Optical model analyses (within a Woods-Saxon-folding model) lead to large differences between the 44Ca and 4~ parameters. Furthermore, in our parametrization, the 4~ real potential depth shows dramatic changes with energy. This feature seems outside the domain of the optical model and requires consideration of additional effects (e.g. antisymmetrization) not included in the standard optical model. Present microscopic ,calculations on the basis of the Resonating Group Method are discussed in connection with the characteristic features of e-scattering from 4~