To probe small bones for the secrets of their structure, scientists used to labor over photographs with rulers. Now, through digital imaging, researchers can easily alter colors to highlight subtle features, or apply computer algorithms to calculate the growth rate of the layers of tissue.

Though created for scientific reasons, said Dr. Timothy G. Bromage, a professor at Hunter College in New York, such digitized images have an incidental quality: beauty.

Images of bones, teeth and scales produced by the college's Analytical Microscopy and Imaging Center, run by Dr. Bromage, are now on view at Hunter as part of an exhibit, ''The Microscope and the Skeleton.''

The specimens were illuminated under various types of microscopes, including X-ray and electron, then were captured by digital sensors, much like those in digital cameras.

A C.T. scan of a jaw of Homo rudolfensis, a hominid that lived about two million years ago, shows its teeth, designed for grinding tough plants, had a much thicker layer of enamel than ours.

Portions of two fish scales are blown up into wall-size banners, the scales' microscopic patterns transformed into surrealistic calligraphy. In one, the patterns are regular and rhythmic; in the other, the patterns are frantic and disordered. The two fish are the same species -- except the latter lived in water tainted by radiation from Chernobyl.

The free exhibition continues through Saturday.

Photos: This cross-section of a human thigh bone is made up of more than 250 polarized light images formed into one high-resolution view. (Haviva M. Goldman); The skeleton of a genetically manipulated mouse embryo that was used for research. (Timothy G. Bromage and Nancy Yeh); A thin section of a molar from a medieval human in present-day Denmark, above, serves as a natural record of life history. The tooth's enamel is often well-preserved in archaeological contexts. (Rebecca J. Ferrell); Left, the width between scales of a fish that had flown on a space shuttle offered evidence about the fish's reaction to zero gravity. The growth rate seemed little changed, implying the possibility of developing aquaculture in space. (Timothy G. Bromage)