  Recent data on the Nachtmann moments of the unpolarized proton structure
function F2p, obtained at low momentum transfer with the CLAS detector at
Jefferson Lab, are interpreted in terms of the dominance of the elastic
coupling of the virtual photon with extended substructures inside the proton.
The CLAS data exhibit a new type of scaling behavior and the resulting scaling
function can be interpreted as a constituent form factor consistent with the
elastic nucleon data. A constituent size of ~ 0.2 - 0.3 fm is obtained.
