Critique

Abstract

The reader may have noticed in several instances what may have seemed to represent a pessimistic attitude toward the future of research on some of these topics. On occasion it might be suggested that the author should have used a subtitle such as: What is not known about apatite. Facetiously, the rejoinder to such an appraisal would have to be: One could not write a book on what is not known on this subject because many volumes would be required in order to accomplish such a task. However, in order to sustain an interest in research on any particular topic for more than three decades, one must surely have an optimistic viewpoint, despite the fact that the road he travels may be a most lonesome one.