  We present an experimental method for the in-situ observation of
directional-solidification fronts in bulk samples of transparent eutectic
alloys. The growth front is observed obliquely in dark field through the liquid
and a glass wall of the container with a long-distance microscope. We show that
a focused image of the whole growth front can be obtained at a certain tilt
angle of the microscope. At this tilt angle, eutectic fibers of about 3.5\mic
in diameter can be clearly seen over the whole growth front in 400-\mic thick
samples.
