viii PREFACE. , 



The observations forming the basis of the work were made 

 in the course of the cruise of tlie Wilkes Exploring Expedi- 

 tion around the world during tlie four years from 1838 to 

 1842. The results then obtained are published in ,my Report 

 on Zoophytes, which treats at length of Corals and Coral 

 Animals, and in a chapter on Coral Reefs and Islands form- 

 ing part of my Cieological Report. 



The opportunities for investigations in this department 

 afforded by the Expedition were large, ^^'e visited a number 

 of the coral islands of the Paumotu Archipelago, to the north 

 of east from Tahiti ; also some of the Society, Navigator, and 

 Friendly Islands, all remarkable for their coral reefs ; the 

 P'eejee Group, one of the grandest regions of growing corals 

 in the world, where we spent three montlis ; several islands 

 north of the Navigator and Feejee Groups, including the 

 Gilbert or Kingsmill Group ; the Sooloo sea, between Borneo 

 and Mindanao, abounding in reefs ; and, finally, Singaj)ore, 

 another P^ast India reef-region. 



Most agreeable are the memories of events, scenes and 

 labours, connected with the cruise : — of companions in travel, 

 both naval and scientific ; of the living things of the sea, 

 gathered each morning by the ship's side and made the study 

 of the day, foul weather or fair ; of coral islands with their 

 groves, and beautiful life, above and within the waters ; of 

 exuberant forests, on the mountain islands of the Pacific^ 

 where the tree-fern expands its cluster of large and graceful 

 fronds in rivalry with the palm, and eager vines or creepers 

 intertwine and festoon the trees, and weave for them hangings 

 of new foliage and flowers ; of lofty precipices, richly draped, 

 even the sternest fronts made to smile and be glad, as delights 

 the gay tropics, and alive with waterfalls, gliding, leaping, or 

 plunging, on their way down from the giddy heights, and, 

 as they go, playing out and in amid the foliage ; of gorges 

 explored, mountains and volcanic cones climbed, and a burn- 

 ing crater penetrated a thousand feet down to its boiling 



