AGASSIZ: FIJI ISLANDS AND CORAL KEEFS. 41 



considered by itself, and that no sweeping generalization can take in 

 the formation of all coral reefs. Such atolls as those of Alacran on the 

 Yucatan Bank of the Hogsty Reef in tlie Bahamas owe their origin — 

 I mean the conditions existing there now — to entirely dilierent causes 

 from those which have brought about the formation of some of the atolls 

 of Fiji, and the atolls of Alacran and of Hogsty themselves again owe 

 their origin to different causes. The barrier reef of Florida does not 

 owe its origin to the same causes as those which have led to the forma- 

 tion of the Great Barrier Beef of Australia, or tlie barrier and friniriuff 

 reef surrounding parts of Viti Levu, or some of the other islands of the 

 Fiji group. 



It is playing wnth words to call such atolls as I have mentioned above 

 pseudo atolls, as is becoming the fashion, and to speak of the localities 

 to which Darwin's theory of the formation of barrier reefs and of atolls 

 does not apply as exceptions to the rule. These exceptions now cover a 

 good deal of ground. They include nearly all the coral reefs which 

 have been examined by recent investigators, — from Semper in the 

 Pelew Islands, Rein in the Bermudas, Murray in Tahiti and elsewhere, 

 of Forbes, and of Bourne, of Guppy in the Solomon Islands, Kramer in 

 Samoa, and others, — down to my own in Florida, the Yucatan Bank, 

 Cuba, Bermuda, the Bahamas, and the West India Islands, as well as in 

 the Galapagos and Sandwich Islands, besides the exploration of the 

 Great Barrier Reef of Australia, and of the Fiji Islands. Surely the list 

 of investigators and of localities is long enough. The negative evidence 

 is now becoming overwhelming, and the recent borings at Funafuti have 

 not weakened the position of those who do not recognize the Darwinian 

 theory as of universal application, and as not having been proved to 

 exist in a single instance, either by a careful examination of the locality 

 or by borings. 



Taviuni. 



Plates 4, 18, 60. 



The islands of Taviuni (Plates 4, 18) and of Kandavu (Plates 10, 11) 

 illustrate admirably the formation of reefs encircling denuded and eroded 

 extremities of large islands, and readily explain the existence of very 

 irregularly shaped reefs representing the former outline of the islands 

 which they replace. Other characteristic points similar in their origin 

 ai'e the great spits forming the Namena Barrier Reef, which connects 

 with the extensive reef platforms reaching towards Ovalau from the 

 southeastern extremity of Vanua Levu (Plates 3, 3*) and the north- 



