Biological stereology: history, present state, future directions.

The development of a quantitative structural platform for experimental biology--extending across a hierarchy of sizes ranging from molecules to organisms--has been punctuated by a series of major achievements over the last 30 years. Stereology, a form of quantitative morphology, has contributed handsomely to this success. A personal view is presented highlighting key events in the development of biological stereology. We also examine stereology with a view toward future developments in biology and speculate how stereology might contribute to the new biological infrastructure currently being built with computers.