  We report video-microscopy measurements of the translational and rotational
Brownian motions of isolated ellipsoidal particles in quasi-two-dimensional
sample cells of increasing thickness. The long-time diffusion coefficients were
measured along the long ($D_a$) and short ($D_b$) ellipsoid axes, respectively,
and the ratio, $D_a/D_b$, was determined as a function of wall confinement and
particle aspect ratio. In three-dimensions this ratio ($D_a/D_b$) cannot be
larger than two, but wall confinement was found to substantially alter
diffusion anisotropy and substantially slow particle diffusion along the short
axis.
