An interesting account of the folklore and myth associated with the loss of the first tooth introduces the paper. This is followed by an analysis of these universal mental productions. The author, utilizing many references from Freud and other psycho-analytical writers, shows how the loss of the tooth enhances castration anxiety. A number of case histories are presented to support this hypothesis. Lewis suggests that the shedding of the first tooth may play an important part in primary and secondary repression and thus in the production of childhood amnesia.