jS THE GREAT BARRIER REEF. 



subsidence theory, we select the following: " In Kotzebue's Voyage, there are accounts of islands, 

 both in the Caroline and Marshall Archipelagoes which have been partially washed away during 

 hurricanes. A storm lately entirely swept away two of the Caroline Islands, and converted them 

 into shoals ; it also partly' destroyed two other islands. According to a tradition which was 

 communicated to Captain Fitzroy, it is believed that the arrival of the first ship caused a great 

 inundation which destroyed many lives. Mr. Stuchbury relates that in 1S25 the western side of 

 Chain Atoll in the same group was completely devastated by a hurricane, and not less than three 

 hundred lives lost ; in this instance it was evident, even to the natives, that the hurricane alone 

 was not sufficient to account for the violent agitation of the ocean. With respect to Whitsunday 

 and Gloucester Islands, in the Low Archipelago, we must either attribute great inaccuracy to 

 their discoverer, the famous circumnavigator, Wallis, or believe that they have undergone a 

 considerable change in the period of fifty-nine years, between his voyage and that ot Captain 

 Beechy. Whitsunday Island is described by Wallis as 'about four miles long and three wide. 

 Now, it is only one mile and a half long. Blenheim Reef, in the Chagos group, consists of a 

 water-washed annular reef, thirteen miles in circumference, surrounding a lagoon ten fathoms 

 deep ; on its surface there are a few worn patches of conglomerate coral-rock of about the size of 

 hovels, and these Captain Moresby considers as being without doubt the last remnants of islets ; 

 so that here an atoll has been converted into an atoll-formed reef* The inhabitants of the 

 Maldiva Archipelago, as long ago as 1605, declared, 'that the high tides and violent currents were 

 always diminishing the number of the islands.' " 



Here is Mr. Darwin's summary of the whole evidence adduced : — " The facts then stand 

 as follows : There are many large spaces of ocean, without any high lands, interspersed with 

 reefs and islets formed by the growth of those kinds of coral which cannot live at great depths ; 

 and the existence of these reefs and low islets in such numbers and at such distant points 

 is mexplicable, excepting on the theory that their rocky bases slowly and successively sank 

 beneath the level of the sea, whilst the corals continued to grow upwards. No positive 

 facts are opposed to this view, and some direct evidence, as well as general considerations, 

 render it probable." 



Mr. Darwin's very logical chain of reasoning is here supplemented b}' two exceedingly 

 explicit diagrammatic illustrations, which have, from the date of their publication, been awarded 

 a prominent position in every biological class-book. These diagrams, together with the original 

 explanatory text, are reproduced with the courteous permission of the publishers and proprietors 

 of the work, Messrs. Smith, Elder, & Co. 



* It appears to the author just possible that these conglomerate coral-rock boulders, reported by Captain 

 Moresby, have been detached by storm-waves from the outer edge, and thrown on the surface of the platform- 

 reef, as in the lower of the two illustrations in Plate XXX. 



