The arrangement of the principal fibres of the periodontium of the Vervet monkey was investigated. This study indicates that the cemento‐gingival fibres, radiate out from the cementum of the teeth in much the same way as do the cemento‐alveolar fibres. The radiating cementogingival fibres which terminate in the cementum of the adjacent teeth are responsible for the presence of the trans‐septal band which has been described as a distinct fibre group. Other cemento‐gingival fibres decussate with similar fibres from adjacent teeth. In labio‐lingual sections, these decussations give rise to the appearance of cross‐sectional fibres within the longitudinally orientated masses. These cross‐sectional bundles have been described as a separate fibre system known as the circular band. Certain of these radially arranged cemento‐gingival fibres terminate in muscle fibres of the facial musculature. This continuity is well demonstrated in sections which traverse the mucobuccal fold. The significance of the radial arrangement of fibres of the periodontium and the relationship of cemento‐gingival fibres to the facial muscula