TEGETATION OF DIEGO GAECIA. 333 



Bory de St. Vincent (' Voyage dans les quatre Priucipales 

 lies des Mers d'Afrique,' 1804, iii. p. 247), refers to the 

 islands in these words : — " On arme a I'lle de France diverse 

 embarcations, qui ne font d'autre commerce que d'aller a 

 Praslin a Diego Garcias et sur d'autres ecueils chercher des 

 cocos pour en faire de rhuile.'* In 1885, in connection with 

 the expedition of Mr. Bourne, to be referred to hereafter, Prof. 

 Moseley, F.E.S., kindly drew the attention of the Director 

 of Kew to the following extract from Findlay's 'Directory 

 for the Navigation of the Indian Ocean,' 2ud ed. London, 

 1870, p. 459 : — " On nearly every part of these islands there 

 grow at intervals great clumps of gigantic trees, the Bois 

 Mapan or Eose Tree, which attains an enormous size and height, 

 even to 200 feet. Their growth and decay is most rapid, and 

 their fallen and decayed trunks form a large portion of the vege- 

 table world of the Archipelago." This statement increased our 

 desire that the islands should be explored botanically. In 1883 

 an opportunity occurred. H.M.S. * Moorhen' was to call at 

 Diego Garcia on her homeward voyage from China ; and at the 

 instigation of Mr. Wykeham Perry (Secretary to the Commodore 

 in Chief, China Station), Mr. A. Hume (Assistant Paymaster, 

 K.N.) made a small collection of plants there and forwarded 

 them to Kew. This collection, although regarded as very im- 

 perfect by Mr. Hume, dispelled to a great extent the idea of the 

 existence of endemic forms, as it consisted entirely of the com- 

 monest of tropical littoral plants. Nevertheless it did not con- 

 clu>ive]y prove that the flora was wholly of comparatively recent 

 derivation, and as Diego Garcia had by this time been made a 

 coaling-station of the ' Orient ' line of steamers from London to 

 Australia, an opportunity for a more complete exploration was 

 Dot far distant. In 1885 Mr. Gilbert C. Bourne, F.L.S., was 

 furnished with funds by the Government Grant Committee of 

 the Eoyal Society for investigating the njarine invertebrate fauna, 

 and he at the same time undertook to botanize the islands. This 

 he appears to have done thoroughly ; but before proceeding to 

 discuss his collection, I will here give some particulars concerning 

 the islands, communicated by Mr. Bourne, 



*' Diego Garcia," he writes, "is an Atoll fourteen miles long 

 by six miles and a half broad, entirely of coral formation, and 

 nowhere rising more than ten feet above high tide, excepting 

 where, in a few places, sand heaps have been piled up by the 



