  We compute the emission spectrum of minimally coupled particles with spin
that are Hawking radiated from four dimensional black holes in string theory.
For a range of the black hole parameters the result has a product structure
that may be interpreted in terms of the respective right- and left-moving
thermal correlation functions of an effective string model. For spin-one and
spin-two particles a novel cancellation between contributions to the wave
function is needed to ensure this outcome. The form of the spectra suggests
that the four-dimensional effective string description is ``heterotic'':
particles with spin are emitted from the right-moving sector, only.
