CANINE ROOT DEVELOPMENT AND MORPHOLOGY IN MACACA-NEMESTRINA

Recently, YOSHIKAWA and DEGUCHI (1992) reported an unusually high freq uency (40%) of two-rooted maxillary canines in Macaca fuscata females and a complete absence of this trait in males. In the present study, c anine root development and morphology was examined using cephalo-graph s taken on 50 male and 50 female Macaca nemestrina, and 20 male and 20 female Papio cynocephalus for comparison with the Japanese macaque. T he results showed no double-rooted canines present in either species i n the upper or lower canines. This supports the general rule that, amo ng primates, canines possess a single-root. It was further suggested t hat the two-rooted canines in M. fuscata may be the result of the foun der effect, i.e. that the genes for this trait may have been carried b y the initial populations when they arrived on the islands sometime du ring the middle to late Pleistocene.