September 1, 1896.] 



KNOWLEDGE 



209 



greater part of which has disappeared before cultivation 

 and fires. Still, sufficient is left in the less accessible 

 places to give an idea of the composition of the aboriginal 

 vegetation. Some three hundred and fifty species of 

 flowering plants and ferns are recorded from the islands, 

 one-sixth of which have not been found elsewhere. Palms 

 and screw pines constitute the most striking features in 

 the vegetation ; the former, indeed, exhibiting a more 

 numerous and varied development than in any similar 

 situation in the world. The only approach to it is in 

 Lord Howe Island, a speck of land less than a quarter of 

 the size of the Isle of Wight, situated in mid-ocean, about 

 three hundred miles from the coast of New South Wales. 

 This island, however, is some ten degrees out of the 

 tropics, yet it produces four species of palms peculiar to 

 itself. It is probable that Eastern Polynesia formerly 

 possessed a more varied palm vegetation than at present, 

 because, apart from the universal coconut, individuals of 

 several other kinds are now of rare occurrence, whilst 

 others may have disappeared altogether. 



But to return to the palms of the Seychelles, which, I 

 may mention in passing, are admirably depicted in the 

 Marianne North gallery of paintings at Kew, and most of 

 them may also be seen growing in the large palm house. 

 Including the coconut, nine distinct kinds of palm inhabit 

 these islands, and seven out of the nine have not been 

 found elsewhere. Specially noteworthy among these palms 

 is the double coconut, or coco de mer, Lodoicea sechellarum, 

 whose huge, curiously formed fruits were known long 

 before the tree that bears them was discovered. Like the 

 coconut, it has an outer fibrous covering and an excessively 

 hard inner shell. Usually, when divested of its outer 

 covering, it is a two-lobed body, consisting of two oblong 

 lobes side by side. Sometimes it is three, four, or five-lobed, 

 and very rarely six ; and then about eighteen inches in 

 diameter. There is a fine series of this singular production 

 in Museum No. 2, at Kew, and young living plants of 

 the palm in the Victoria and palm houses. 



It was not until very nearly the middle of the last 

 century that the home of the double coconut was discovered. 

 Previously the nuts had been discovered floating in various 

 parts of the Indian Ocean, and most fabulous accounts of 

 their origin and virtues were given, even by writers of 

 some repute. Among other things the tree was supposed 

 to grow at the bottom of the sea, and enormous prices 

 were paid for the nuts by Asiatic and even some European 

 potentates. 



Though not so graceful and elegant as many other 

 palms, the double coconut is a handsome and striking 

 object, having a very slender unbranched trunk, from fifty 

 to a hundred feet high, crowned with a tuft of broad, 

 plaited leaves. The male and female flowers are borne 

 on difl'erent individuals, and the nuts hang in clusters at 

 the base of the leaf stalks. It is, or was, common only in 

 Praslin Island, growing singly and in groups on the rocky 

 hills, often almost overhanging the sea. 



I will now take the reader to the historically interesting 

 Island of St. Helena, in the Atlantic ; a rugged, rocky 

 island, rising nearly three thousand feet above the sea, and 

 having an area of twenty-eight thousand acres. Its isola- 

 tion is extreme, being upwards of a thousand miles from 

 the coast of Africa, and nearly two thousand miles from 

 the nearest point of the American continent. When first 

 discovered it was entirely clothed with forests, but no 

 mammals of any kind inhabited the island. As was 

 customary in those days, hogs and goats were introduced, 

 in order to provide food for chance visitors in the future. 

 The goats especially multiplied to such an extent that 

 they destroyed the vegetation, or at least prevented 



seedhngs to grow up and replace that removed by decay 

 or felling. The aboriginal vegetation consisted almost 

 entirely of woody plants and ferns, the bulk of the former 

 belonging to the great family Composite, of which the 

 daisies and asters are familiar examples. 



It was not until the beginning of the present century 

 that the island was thoroughly botanized, and it is possible 

 that some of the native plants had already disappeared ; 

 at all events, many were already very rare. In 1875 an 

 exhaustive account was published of the condition of the 

 then almost entirely displaced native plants, as well as of 

 the plants that had replaced them. At that date less than 

 half a dozen of the sixty-five certainly indigenous species 

 of flowering plants and ferns collected in the island at 

 the beginning of the century were actually extinct ; yet, 

 with the exception of a few scattered individuals, the only 

 remnant of the former flora was high up in the central 

 ridge of mountains and in inaccessible parts of the island. 

 Trees that once covered hundreds of acres were reduced to 

 a few individuals ; some to a single example. Large areas 

 once covered with vegetation are now bare, in consequence 

 of the rains having washed the soil from the rocks. In 

 other parts the ground has been completely taken posses- 

 sion of by introduced plants from various parts of the 

 world, prominent amongst which are many British species. 

 Our common furze is now the most abundant shrub in the 

 island, afi'ording employment to many natives, who cut it 

 and take it into the town to be used as fuel. Among 

 trees the British oak is one of the most thoroughly 

 naturalized, growing to a great size and producing acorns 

 in profusion ; and the Scotch fir and alhed species had 

 been planted to the extent of two hundred acres in 1875. 

 Thus has nearly the whole surface of the island been com- 

 pletely altered ; and soon, doubtless, most of the original 

 plants of the island will be extinct, for they exist nowhere 

 else in a wild state, and those in cultivation are diflicult 

 to preserve. 



Although St. Helena is rather less than fifteen degrees 



south of the Equator, the general character of the aboriginal 



liora is not even subtropical. It is like the remains of an 



intertropical mountain flora, and turning again to Lord 



) Howe Island for comparison, no greater contrast could be 



] found. This island is situated in 31" 80' S. latitude, yet its 



: vegetation consists largely of tropical types, such as 



palms, screw pines, banyans, and epiphytal orchids. 



These dififerences suggest many interesting deductions, 



among others a much greater antiquity for the flora of 



St. Helena. 



As already pointed out, a very large proportion of the 

 native plants of such tropical islands as the Seychelles 

 and St. Helena are peculiar to the respective islands, and 

 this holds good for many other islands and groups 

 of islands ; the Galapagos and Sandwich groups, for 

 example. 



The opposite extreme is found in the numerous coral 



[ islands of the Indian and Pacific Oceans, where there are 



I absolutely no endemic or peculiar plants, and the species are 



nearly all the same, whether we go to the Keeling Islands, sis 



hundred miles off the coast of Sumatra (rendered famous 



by Darwin's visit some sixty years ago), to the Ohagos 



j Archipelago in the centre of the Indian Ocean, or to 



Caroline Island, upwards of eight thousand miles eastward 



ill the middle of the racific. Many of the same plants 



are also found on continental seashores throughout the 



tropics, where the conditions are favourable ; but to a 



less degree in the .Atlantic than elsewhere. Many of these 



bocalled islands are really atolls, or rings of islets, rising 



only a few feet above high-water level, and enclosing a 



central lagoon of varying extent, ranging from a mile 



