82 I'llOCEEDINGS OF THE 



vef^elablo drift cast ashore during violent storms. 13 species, 

 witli more or less fleshy fruits, were probably carried to the 

 islands by frugivorous birds. lu this group is included all the 

 trees of JSerimula, and among them the cndcmii' Sabal, which he 

 considers to be, like tlie other endemic ])lants, only the differ- 

 entiated descendant of the same stock as the respective allied 

 species on the American Continent. And lastly, 21' species which 

 are probably indigenous, but may have been introduced by man. 



Mr. Hemsley describes the gradual accession of the various 

 elements of a flora in a new coral island, and he holds that with- 

 out the action of ocean currents and birds the numerous remote 

 coral islands would be utterly devoid of phanerogamic vegetation. 



More recently our Foreign Member, Dr. Treub, of Buitenzoig, 

 has examined the beginning of vegetation on the fragments of 

 Krakatao that remained after the extraordinary explosion and 

 volcanic outburst of August 1883. The present island is a 

 mountain rising about 2500 feet out of the sea almost perpen- 

 dicularly on one side, and Avitli an inclined slope and very narrow 

 beach on the other. In 1883 Krakatao was covered from tlie 

 summit to below the sea-level with a continuous layer of ashes 

 and burning pumice, varying from 3 to 200 feet in thickness, so 

 that every vestige of life on the island was destroyed. As the 

 island is uninhabited and uninhabitable, man has had nothing to 

 do with the appearance of the new vegetation. Krakatao is 

 distant 10 miles from the island of Sibesia and about 20 miles 

 distant from both Sumatra and Java. Dr. Treub found in June, 

 1886, a littoral flora grown from ocean-carried seeds, and con- 

 sisting of 9 species, all of them, with the exception of the Javan 

 Grass, belonging to the list of plants which stock new coral 

 islands within the tropics. These were : — 



Erytbi'iua sp. 



Calojihylluiu luophyllum, LinU: 

 Oerbera Odallam, Gacrtn. 

 Hernandia >Sonora, Linn. 

 Ipouijea Pes-Cai^rn.', tiw. 

 Sca'vola Koeiiigii, Vahl. 

 2 species of Cyperaceaj. 

 Gymnotbrix elegans, JJlisc. 



The surface of the island Avas covered almost everywhere with 

 a thin layer of Confcrvoid Alga? belonging to six species. Three 

 were species of Lynyhya, aud one each of Tohjpothrix, Anabana, 

 and Symjjloca. 



Besides two Mosses, Bv. Treub found eleven species of 

 Ferns : — 



Gyiiinograinme Calomelanus, KaulJ. 

 Blecbmuu orientale, Linu. 

 AcrosticbuiM scaiideus, J. Sm. 



aureum, Cim. 



Plcris longilblia, Linn. 

 Xfpln-dlciiis oxaltahi, Sthoft. 



