TRFK. 361 



cannot be used by vessels of any size. Pis Island is flanked on the sea face 

 by a high coarse shingle beach, while on the lagoon side it is edged with a 

 magnificent beach of fine coral sand of considerable height, on which the 

 natives draw up their canoes. The islands on the northern face have been 

 thrown up by the combined action of the trades, the sea and swell from' 

 the lagoon side. The spits at the extremity of the islands on the north 

 face of the atoll of Truk are generally covered with niasses of boulders ; 

 deep water separates some of the smaller islands on the inner side of the 

 barrier reef flats of the lagoon, showing that this part of the lagoon was 

 at one time a reef flat similar to that to the west and to the east, merely 

 flanking the inner coral patches which have now become more or less 

 connected with the outer land rim, forming as it were small secondary 

 lagoons similar to those we have described elsewhere. 



The island of Pis is covered with magnificent vegetation and is one of 

 the most thickly populated of the islands in the Carolines ; the natives 

 living there have but little contact with the settlements at Uola and the 

 southern part of Truk. 



On the larger volcanic islands the vegetation reminds one more of the 

 vegetation of the eastern continental islands; it is even more luxuriant 

 than that of Kusaie or of Ponapi. Judging from the little that is known of 

 the larger forest trees, it is evident that the flora has felt the influence 

 of its greater proximity to that of the East. We are constantly reminded of 

 the similarity between the flora of the Malay Archipelago and the flora 

 of the Carolines, a similarit}- gradually becoming less marked as we go 

 east to Ponapi, to Kusaie, and to the Marshall Islands. This relationship 

 appears still more striking when we take a more southerly course and pass 

 east through Fiji, Samoa, and the Cook Archipelago to the Society Islands, 

 where it is difficult to recognize that part of the flora which owes its origin 

 to a migration from the west to the east. 



On examining a chart of the Carolines, we notice that the central part of 

 the Carolines occupies an area where denudation and erosion have been far 

 more active than it has been at the eastern and at the western extremities 

 of the group. On the east the islands of Ponapi and of Kusaie rise to the 

 heif^ht of nearly 3000 feet, and on the west such islands as Yap and the 



