334 MB. W. BOTTING HEMSLET ON THE 



w iiid. The riug of land encircling the lagoon is nearly continuous, 

 and averafi:es one third of a mile in width. At the north end 

 the strip of land is discontinuous; here there is an entrance into 

 the harbour five miles wide, broken up by three small islets into 

 four channels. The whole of the main island is densely covered 

 with vegetation, Sccevola Koenigii and Tourncfortia argentea 

 reaching down to the high-tide level on either shore, and forming, 

 especially the Sccevola^ a thick impenetrable mass along both 

 shores. Within this mass of bushes come cocoa-nut palms, 

 which have been artificially planted only in a few places ; over 

 the larger part of the island they have grown wild- The under- 

 growth beneath the palms is often very thick, consisting generally 

 of Guettarda speciosa. There are no cocoa-nut trees on the three 

 islands in tlie mouth of the harbour; but the whole of the main 

 island is densely covered with them. I have frequently seen 

 cocoa-nuts germinating on the shores in places where the young 

 plant was lapped by the waves at the highest spring-tides ; these 

 young plants seemed to be perfectly healthy. The shores are 

 not, I should think, favourable for the germination of many 

 kinds of seeds that may be fortuitously brought to them, being 

 composed almost entirely of coral blocks or coral-sand. There is 

 a little cultivation in the island at the tliree principal habita- 

 tions of Point Marianne on the west side of the island, and East 

 Point and Minny Minny on the east side. In the Gardens 

 bananas, sweet potatoes, bitter oranges, citrons, and a few other 

 tropical fruits are grown. Maize is cultivated at Minny Minny. 

 I, have forgotten to mention that the banyan tree occurs on the 

 island. There are several large specimens, but it docs not appear 

 in my collection, for it neither flowered nor fruited during my 

 stay. The only noticeable feature about it is that, owing no 

 doubt to the poverty of the soil, its leaves are much smaller than 

 usual." 



In connection with the vegetation of oceanic islands generally 

 I published a list of the plants collected by Mr. Hume in the 

 Botany of the ' Challenger ' Expedition, part 3, p. 115, omitting, 

 however, to add the sign of doubt after the name Achyraiithes 

 velutinay Hook, et Arn. This list and the collections sent by Mr. 

 Bourne the latter part of last year and the beginning of this, 

 prove that the flora of Diego Garcia is altogether derivative, and 

 apparently of comparatively recent derivation. The fern, Asjple- 



