270 A NATURALIST IN THE PACIFIC chap. 



and the Chilian Strawberry (Fragaria chilensis). If he has been 

 in New Zealand and in the islands of the Southern Ocean he will 

 find old friends in the genera Acaena and Coprosma. He may- 

 handle once again plants like Nertera depressa, that he gathered 

 on Tristan da Cunha ; and on the boggy summits of some of 

 the mountains he will find the ubiquitous Sun-dew (Drosera 

 longifolia). 



Within the limited area occupied by the peaks of Tahiti he 

 will find genera like Astelia and Coprosma that are at home 

 in New Zealand or in Antarctic America, and may even find, as in 

 the cases of Coriaria ruscifolia and Nertera depressa, the identical 

 species that are at home in those distant regions. Even on the 

 summit of Rarotonga he will gather a species of Vaccinium. In 

 Fiji, here and there on some isolated mountain-top he may come 

 upon a remnant of this Antarctic flora, such as a solitary species of 

 Coprosma or Lagenophora, that will carry him back for a moment 

 to high southern latitudes ; and in the highlands of Savaii, in the 

 neighbouring Samoan Group, he will find again Nertera depressa 

 and a species of Vaccinium. But that which will interest him 

 most in Fiji will be the tall conifers of the genera Dammara, 

 Podocarpus, and Dacrydium, which will bring to him memories 

 perhaps of New Zealand and southern Chile, of South Africa, and 

 of the mountain-woods of Java and of Southern Japan. 



Yet the influence of isolation has been at work amongst the 

 mountain-plants of all these groups. The agencies that have 

 dispersed over the tropical Pacific plants from the cold latitudes 

 of the southern hemisphere, and those that have borne the seeds 

 of Plantago, Sanicula, and Vaccinium from mountain-top to 

 mountain-top, even though it be to a peak in mid-ocean, are to a 

 great extent inactive now. 



The Mountain-Flora of Hawaii as illustrated by the 



Non-endemic Genera. 



Let us look in the first place at Hawaii, where the breaking off 

 of communication with the outside world is especially pronounced. 

 Here, all the species of two-thirds or more of the mountain-genera 

 are confined to that group. Only in a relatively small number of 

 cases are the species in touch with the regions outside. The 

 mystery of disconnection that is so evident in the instance of 

 the peculiar or endemic mountain-genera of the Compositas and 

 Lobeliaceae and other orders is here again presented to us, and 



