GENERAL ACCOUNT HEDLEY. 21 



is almost universally distributed in the tropical islands of the 

 Pacific can scarcely aid us in the matter. If, however, we can 

 find a littoral plant that has only partly performed the traverse 

 of this region, then we shall possess in the interrupted operation 

 an important piece of evidence. The Mangrove (Rhizophora, 

 Bruguiera, &c.) is absent, or very rare, in Eastern Polynesia, 

 but unfortunately for our purpose this is in great part explained 

 by the lack of a suitable station on the precipitous shores of the 

 larger islands. We have, however, in Nipa fruticans a plant 

 well fitted for our object, and one well known to be dispersed by 

 the currents. . For a littoral species it has a limited range. It 

 is found on the tropical shores of Asia, east of the Ganges, and 

 in the Indian Archipelago, where it abounds ; and there is no 

 question as to its great antiquity in this region. Now the Nipa 

 Palm, as it is sometimes termed, has attempted to reach Polynesia 

 by two routes from the Indian Archipelago, viz., by Melanesia 

 and Micronesia. Along the first route it has in the course of 

 ages reached the Solomon Islands, where I found it in 1884. 

 Along the second route it has extended its range to Ualan or 

 Kusaie, at the eastern end of the Caroline Group, where it was 

 observed by Kittlitz about seventy years ago. Since its intru- 

 sion so far into the Pacific seems to have escaped the notice of 

 later botanists, and as no reference is made to it by Hemsley in 

 his account of the floras of oceanic islands, given in his ' Botany 

 of the " Challenger," ' I may here remark that it is described in 

 general terms in the narrative of Kittlitz, and is figured in his 

 ' Views of the Pacific Vegetation,' where it was also identified 

 and noted by Dr. Seemann in his English edition of the ' Views.' 

 Now the island of Kusaie lies in the course of the Pacific Counter 

 Current, which runs to the eastward from the Malay Archipelago 

 right across the Pacific between the parallels of about 4 to 8 N. 

 Here the Nipa Palm has reached the last spot where it could find 

 a station. Beyond lie the coral atolls of the Marshall Group that 

 could afford no home to a plant that frequents the extensive coast 

 swamps, and lines the mouths of large rivers in Asia and in the 

 Archipelago. Most of the familiar littoral plants of Polynesia 

 have probably reached their present home by the path attempted 

 in vain by the Nipa Palm. Since they for the most part frequent 

 coral islands, the atolls of the Marshall, Gilbert, and Ellice Groups 

 would form so many stepping-stones by which, in the season of 

 the north-west winds, they would be able to find their way to 

 Samoa and Fiji in spite of the westerly drift of the Equatorial 

 Current."* 



* Among Mollusca the Trochomorph<e would seeru to have " reached their 

 present home by the path attempted in vain by the Nipa Palm ;" and 

 Rhysota sowerbyana, Pfr., to have accompanied the Nipa to the Carolines, 

 and like it to have there " reached the last spot where it could find a 

 station." C.H. 



