Abstract The great improvements in the methods of histological research which have been developed during the last fifty years have very largely added to our knowledge of the peripheral distribution of the nerves in the various tissues and organs of the body. The mode, however, in which sensory impressions are conveyed from the hard dentine of the human tooth, which clinical experience shows to be highly endowed with sensibility, is not yet thoroughly understood. The difficulties attending the investigation of the relations between the nerve terminations and the calcified dental tissues are perhaps greater than those met with in tracing nerve tissue in other parts of the body, chiefly owing to the delicate connection between the soft pulp and the dentine, and the confusing optical effects produced in the latter tissue by its tubular structure.