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conceivable numbers, of more consequence than gene- 

 rally supposed : it is to the accumulated myriads of 

 them that we owe part of the island on which we live; 

 our hills are in many places full of them, and some 

 rocks are entiiely of their formation. New Islands 

 have been formed within the memory of persons now 

 living; and many seas arebecommg every year more 

 difficult to navigate, being nearly choaked up by the 

 habitations of animals almost too small for human 

 perception. 



*' The whole groupe of the Thousand Islands, and 

 indeed the greater part of those whose surfaces are 

 flat, in the neighbourhood of the Equator, owe their 

 origin to the labours of that order of marine worms 

 which Linnffius has arranged under the name Zoo- 

 phyta. These little animals, in a most surprising 

 manner, construct their calcareous habitations under 

 an infinite variety of forms; yet with that order and 

 regularity, each after its own manner, which, to the 

 minute inquirer, is so discernible in every part of the 

 creation. But, although the eye may be convinced 

 of the fact, it is difficult for the human mind to 

 conceive the possibility of insects so small being en- 

 dued with power, much less of being furnished in 

 their own bodies with the materials for constructing 

 the immense fabrics, which, in almost every part of 

 the Eastern and Pacific oceans, lying between the 

 Tropics, are met with in the shape of detached rocks, 

 or reefs of great extent, just even with the surface ; 

 or islands already clothed with plants, whose bases 

 are fixed at the bottom of the sea, several hundred 

 feet deep, where light and heat, so very essential to 

 animal life, if not excluded, are sparingly received 

 and feebly felt. Thousands of such rocks, reefs, and 

 islands are known to exist in the Eastern ocean, 

 within, and even beyond the limits of the Tropics. 



