  The critical fluctuations of CuGeO$_3$ have been measured by synchrotron
x-ray scattering, and two length scales are clearly observed. The ratio between
the two length scales is found to be significantly different along the $a$
axis, with the $a$ axis along the surface normal direction. We believe that
such a directional preference is a clear sign that surface random strains,
especially those caused by dislocations, are the origin of the long length
scale fluctuations.
