SEASONS, LEAFING, FLOWERING & FRUITING 29 many times, covering most months, from 1929-1940. The ridge, athwart the monsoons, is exceptionally wet and probably accounts for the higher rainfall of Kota Tinggi. January was the only month when dry weather could be expected; otherwise, on most days, heavy rain would begin about 11 a.m. and last well into the afternoon. I noted, nevertheless, dry weather on the ridge in March-April 1931. To this abundant rain and cloud-cover the ridge owes its peculiarity of lowland swamp-forest and mountain Leptos per mum-forest (p. 36). With the opening of the new year, various trees in the swamp-forest began to change leaves and to flower. From January on there was a succession of flowering even into the wet weather of November and December when some species of Calophyllum and of rengas flowered. The canopy was never wholly in flower and, thus, individual trees could be picked out and their specific abundance recognised. The period of flowering for any one species was 3-5 weeks, after which fruits ripened in 3-6 months. January to May was the best flowering season, and May to October the fruiting. Double flowering ocurred with Tristania sumatrana, the two species of Buchanania, and Ixora grandifolia in Jan.-Feb. and in July-Aug. The shrub Kopsia singapurensis and the shrubby species of Ixora flowered copiously in the forest-undergrowth in Jan. -Feb. and Sept. -Oct. Pentaspadon officinalis, Pterospermum javanicum, and, perhaps, Mesua rosea flowered about April and October. Since these double flowerings were so general, I assumed without proof that the individual plants flowered twice a year. When Kopsia and Ixora flowered, the undergrowth became a mixture of white and orange-red, which seemed to me as good a mark as any of the double climate. Perhaps the species of Nephelium and Xerospermum flowered twice. In contrast, the single annual rhythm was shown by the undergrowth tree Macaranga baccaureifolia which shed its leaves in February (p. 187). Exceptions to the annual rhythm were few, though outstanding, and I think that many more remain to be discovered. As is well known, a general flowering of dipterocarps occurs at intervals of 3-4 years, especially when preceded by a very dry spell. Medway (1972) records the flowering of various dipterocarps in Selangor on 1-3 occasions during the seven years 1963-1969. Burgess (1969 records the fruiting of Shorea curtisii every 7-10 years after severe drought. I noted a general flowering of dipterocarps in the Sedili region only in May 1935 when January had been exceptionally dry. I collected the first fruiting specimens of Kostermansia in Sept. 1932, when there was a general fruiting of this fairly common and immense tree in south east Johore, but I never saw flowers or fruits again until the end of March 1940 when there was a general flowering. I am certain of this because I inspected regularly a group of trees that stood near the beginning of the Jemaluang road. It appears that Kostermansia flowers about March, once in eight years. This appears to be the rate of flowering of lanjut {Mangifera lagenifera), a few trees of which occurred by the Sedili Besar, but I did not observe them in flower. Medway (1972) records the flowering of Gluta renghas in two consecutive years over the period 1963-1969, and three annual flowerings of Swintonia schenkii in the same period. My impression was that several kinds of Anacardiaceae in the swamp-forest seldom flowered. Then I note that fertile material of the large tree P enlace corneri has not been collected, though it is known from Borneo and east Johore. Pentace triptera seemed to flower as seldom as Kostermansia. Medway (1972) recorded two annual flowerings of Pentace strychnoidea in the years 1963-1969. January. The year began with the conspicuous white flowering of Buchanania sessilifolia. As it was finishing in the second half of the month, the crowns of Melanorrhoea wallichii were converted into white mounds of fragrance. The abundance of both species became obvious, though the trees were not gregarious. Towards the end of the month Tristania sumatrana began to flower and the Tristania-banks were whitened for 3-4 weeks. Leaf-fall and the development of inflorescences began in the mempisang-belt.