refractive

Under the one-sixth they appear as slender, highly refractive fibers with double contour and, often, curled or split ends.

Cystin crystals are colorless, highly refractive, rather thick, hexagonal plates with well-defined edges.

Yeast-cells are smooth, colorless, highly refractive, spheric or ovoid cells.

They consist of a more or less dense network of hyph and numerous round or oval refractive spores.

This occurs when, from any cause, such a stratum of air possesses a higher refractive power than the one immediately below it.