  We examine three-dimensional $\pm J$ Heisenberg models with and without
random anisotropies in a magnetic field. We calculate both the stiffness
exponent $\theta_s$ at absolute zero temperature and spin-glass correlation
lengths for the longitudinal and transverse spin components at finite
temperatures. We suggest that, contrary to a chirality scenario predicted by
Kawamura and his co-workers, a Gabay-Toulouse phase transition occurs when the
anisotropies are absent, although no phase transition occurs when they are
present.
