1. Fluorotic bones and exostoses obtained from the skeletons of two subjects with advanced fluorosis have been examined microscopically.

2. The cortical bone showed normal, regular Haversian systems with normal canaliculi and lacunae. The exostoses also exhibited normal, regular Haversian systems but at places the reabsorption tunnels were large.

3. Special stains failed to show osteoid tissue either in the fluorotic bones or in their exostoses.