  Recently Thienel [Ann. Phys. (N.Y.) 280 (2000), 140; quant-ph/9809047]
investigated the Pauli equation for an electron moving in a plane under the
influence of a perpendicular magnetic field which is the sum of a uniform field
and a singular flux tube. Here we criticise his claim that one cannot properly
solve this equation by treating the singular flux tube as the limiting case of
a flux tube of finite size.
