9310624 Ereshefsky Linneaus developed his system of classifying animals and plants to accord with the biological theory of his day, namely a theory based on creationism and essentialism. Linneaus assumed that God created an initial pair of organisms for each species and after God's original creation no new species could arise. Contemporary biology, of course, does not contain such tenets. The source of species is not God but evolution through natural selection and various other biological processes. Despite the abandonment of Linneaus' biological assumptions, the Linnaean System is still the preferred framework for constructing classifications of the organic world. However, with the advent of evolutionary theory, the Linnaean System faces numerous problems that undermine its effectiveness. The Linnaean System has lost its theoretical basis and has become both cumbersome and ontologically vacuous. Yet, there is currently no thorough study of the problems confronting the Linnaean System. Dr. Ereshefsky, under this grant, is providing just such a study. Another aim for Dr. Ereshefsky is to investigate an alternative taxonomic system, namely Willi Hennig's 1969 numerical system. Preliminary work indicates that Hennig's system can overcome many of the problems facing the Linnaean System. ***