  For an electron density near the H=0 insulator-to-conductor transition, the
magnetoconductivity of the low-temperature conducting phase in high-mobility
silicon MOSFETs is consistent with the form
$\Delta\sigma(H_{||},T)\equiv\sigma(H_{||},T)-\sigma(0,T) = f(H_{||}/T)$ for
magnetic fields $H_{||}$ applied parallel to the plane of the electron system.
This sets a valuable constraint on theory and provides further evidence that
the electron spin is central to the anomalous H=0 conducting phase in two
dimensions.
