126 BB. nOOKEB ON THE BOTANY 



sence of a Palm and some Orchidece, of which, however, no speci- 

 mens have hitherto been transmitted. 



Macauley and Curtis Islands are very much smaller, and 

 L'Esperance is a mere rock. 



The most interesting circumstance connected with the vegeta- 

 tion of Eaoul Island is the identity of most of the flowering 

 plants, and all but one of the ferns, that have been collected upon 

 it, with those of New Zealand. The great extent of intervening 

 ocean (450 miles), and the small size of the islands, would appear 

 to render it extremely difficult to account for this similarity of 

 vegetation by transport ; added to which, the prevailing winds 

 blow from the north-west, and the oceanic currents set in the 

 same direction. 



It is also worthy of remark, that of the nine species that are 

 not natives of New Zealand, four are new, and three of these are 

 nearly allied to New Zealand plants ; whilst of those five that are 

 not new, three are widely diffused throughout the tropical and 

 subtropical Pacific islands, and would appear not to be capable of 

 enduring the cold of New Zealand ; these are the Metrosideros 

 polymorplia, Piper latifolium, and Omalanthus nutans. 



The absence of any Ferns (with a single exception) but such as 

 are natives of New Zealand, is, however, a far more striking fact, 

 both because the list is a large one for so small an island (twenty- 

 two species), and because, if their presence is to be accounted for 

 wholly by trans-oceanic transport of these species, the question at 

 once occurs, why has there been no addition of some of the many 

 Fiji or New Caledonian Island ferns, that are common tropical 

 Pacific species, the Fiji Islands being only 700 miles north of the 

 Kermadecs, and New Caledonia 750, The only fern which is 

 not a native of New Zealand, is the Norfolk Island Asplenium 

 difforme. 



Still more remarkable is the total absence in the collection of 

 any of the plants peculiar to Norfolk Island, for Eaoul Island is 

 in the same latitude as Norfolk Island, is exactly the same di- 

 stance from New Zealand, and the winds and currents set 

 from Norfolk to Eaoul Island: in short, though the northern 

 extreme of New Zealand, Norfolk Island and Eaoul Island form 

 an equilateral triangle, with the exception of Asplenium difforme, 

 there is not a single fern of Norfolk Island found in Eaoul Island 

 that is not also found in New Zealand ; whilst of the twenty 

 flowering plants of Eaoul Island, no less than six are absolutely 

 peculiar to New Zealand and Eaoul Island, and with the excep- 



