  We continue to study the `fermion -- 4-vector potential' interactions in the
framework of the McLennan-Case construct which is a reformulation of the
Majorana theory of the neutrino. This theory is shown after applying
Majorana-like anzatzen to give rise to appearance of unusual terms as
\vec\sigma \cdot [\vec A \times \vec A^\ast ], which were recently discussed in
non-linear optics.
