Few cytological data are available of the Loganiaceae. Its subfamily Buddleioideae, often considered a separate family, is a well-defined group, as far as could be concluded from the chromosome number. On the other hand, nothing can be said with certainty of the other subfamily, the Loganioideae, because the available data are still insufficient. Hitherto, the chromosome numbers of the following seven species of Loganioideae, studied by MOHRBUTTER (1936) and Moore (1947), are known: Gelsemium sempervirens 2n = 16 (MOORE, 1947) Strychnos laurina 2n = 24 (MOHRBUTTER, 1936) Strychnos nux-vomica 2n = 24 (MOHRBUTTER, 1936) Strychnos sansibariensis 2n = 24 (MOHRBUTTER, 1936) Spigelia marilandica 2n = 48 (MOORE, 1947) Fagraea fragrans 2n = 12 (MOHRBUTTER, 1936) Fagraea liloralis 2n = 12 (MOHRBUTTER, 1936) These data seem to indicate that the basic chromosome number of the Loganioideae is X = 6.