290 D. Prain — The Vegetation of the Goco Oroup. [No. 4, 



time the surf ceases to break on the edge of the reef practically its whole 

 force rolls in over this even and slightly shallowing reef till it falls on 

 the shore in huge erosive breakers that eat away the soil, so that Fandanus 

 fence, coco-nut zone, and beach-forest all in turn disappear, and the 

 waves at high tide grind on the prostrate stems of huge Mimusops, 

 Ficus Eumphii, and Bipterocarpus trees, and undermine the roots of 

 their old companions that are still standing but that the next storm will 

 lay beside those on the beach. But this active denudation no more 

 indicates a sinking of the land than do the heightened reefs that cause 

 the action indicate that the land has risen, and as direct indications either 

 of rising or of sinking are altogether absent we must conclude that the 

 islands are at present practically stationary. But it is interesting to 

 find, as one does here, in adjacent bays, such diverse indications of the 

 same condition. 



There are bays of a third type in the group, few in number, however, 

 and of small size, in which the water is deep quite up to the beach ; the 

 sweep of the waves in these is extremely large, even when the sea outside 

 is quiet, owing to the strong currents that prevail round the islands. They 

 have all, as might be expected, rocky sides ; the beaches on which the 

 waves break are of sand, not shingle, and owing apparently to this ex- 

 cessive sweep of the waves the Pandamos fence and coco-nut zone at the 

 head of such a bay is a good number of yards away from the beach, a 

 considerable sand-bank covered with Ipomosa biloba, Vigna lutea and 

 other sand-binding species, intervening between the limits of ordinary 

 tides and the woody vegetation. 



The nature of the beaches behind the numerous long, comparatively 

 flat sandstone ledges, exposed at low- water and therefore not coral- 

 covered, has yet to be noted. Such beaches are always of coral-shingle 

 mixed with large shells, the pieces of coral being rounded or oblong and 

 sometimes of considerable size. -The most remarkable example of such 

 a beach in this group is that at the south end and south-east corner of 

 Little Coco where the sandstone reef is particularly extensive and whera 

 the south-west monsoon must break with singular force. This beach 

 consists of an abrupt shingle wall, in many places 6 or 7 feet high, and 

 yet not much wider at the base than twice its own height. Though very 

 steep towards the sea-face it slopes more gradually at the back ; behind 

 it at this point there stretches a low flat tract of muddy land not much 

 higher than the reef itself, covered by a dense jungle of Hibiscus tiliaceics, 

 Vitesc Negundo, Leea, and similar shrubs, but with few trees, the whole 

 loaded with tangled masses of Gassytha. The Pandanus fence is here 

 particularly dense, and along with it are coco-nut trees growing on the 

 shingle ; from the appearance and size of these it seems clear that, slight 



