This volume is the completion of work initially planned several years ago as a compilation of selected aspects of the biological effects of fluorides. The first portion appeared in Volume XXII (1966) of this Handbuch, under the title "Pharmacology of Fluorides, Part 1. " Inasmuch as the present volume is an integral part of the original project, justification for offering it to the scientific community remains the same as that originally set forth...