CORALS 163 



reef, in order that we may in a measure realize the 

 importance of their existence. The Great Barrier 

 Reef, off the east coast of Australia, is 1,250 miles 

 long, with an average breadth of 30 miles. It is an 

 archipelago of coral islands and reefs with many 

 openings, but only twenty-two of which are navigable. 

 Nine only areregularly used for navigation. Numerous 

 creatures of various kinds, such as trepangs, stone-fish, 

 ox-rays, pearl oysters, etc., have their abode in 

 proximity to the reef, so that the fishing grounds are 

 a prolific source of profit to the Government of 

 Queensland, the annual value of the exports being 

 100,000. 



The reef protects the east coast of the continent 

 from the wearing influence of the ocean, and acts as 

 a sieve, in that it retains the silt brought down by the 

 rivers. In time it is likely to add extensively to the 

 area of Australia by its protecting and retaining 

 effects. In fact, the reef is a ' harvest-field, rich from 

 both a commercial and a scientific standpoint.' It 

 only needs the exploration and development of its 

 marvellous resources to bring great wealth to the 

 Government and all connected with it. The sea 

 between it and the continent is equally rich in animal 

 supplies. This enclosed water varies in width from 

 ten miles to one hundred and fifty, and cannot be less 

 than 80,000 square miles in extent the result of the 

 life of microscopic organisms having lived their cycles 

 of life. 



There are various opinions as to the formation of 



