Tooth replacement in the Slow worm (Anguis fragilis)

The dentition of the Slow worm (Anguis fragilis) has been carefully observed in a range of individuals from birth to advanced age. Although a considerable volume of carefully prepared dead material has been used, emphasis in the investigation is placed upon three living specimens kept in near‐natural conditions and examined by taking impressions of the teeth every week throughout a whole season. A general description of the gross anatomy of the dentition is given, and the changes that occur with increasing age. The tooth attachment and the process of replacement in the individual tooth is considered and found to conform to the Anguinomorphan type of replacement described by McDowell & Bogert (1954). The evidence obtained from both dead arid living material as to the pattern and order of tooth replacement is presented and found to be in agreement with the theoryof Edmund(1960). Further details of the replacement pattern, discernible only in the records from the living specimens, and the effects of season and age upon tooth replacement are described. Anguis is found to provide an excellenl illustration of the fundamentalprinciples in reptilian tooth replacement, being relatively uncomplicated in the featuresof its replacement pattern. The species also appears to be a promising subject for the further investigation1 oftooth replacement phenomena.