222 J. D. Dana, Esq., on Coral Beefs and Islands. 



like vegetation upon the land : there are large areas that 

 bear nothing, and others that are thickly overgrown. There 

 is, however, no green sward to the landscape ; sand and frag- 

 ments fill up the bare intervals between the flowering tufts ; 

 or where the zoophytes are crowded, there are deep holes 

 among the stony stems and folia. 



These observations will prepare the mind for some disap- 

 pointment in a first view of coral reefs. Nature does not 

 make greenhouses, but distributes widely her beauties, and 

 leaves it for man to gather into gardens the choicer varieties. 

 Yet there are scenes in the coral landscape which justify the 

 brightest colouring of the poet : where coral shrubbery and 

 living flowers are mingled in profusion ; where Astrsea domes 

 appear like the gemmed temples of the coral w^orld, and 

 Madrepore vases, the decorations of the groves ; and as the 

 forests and flowers of land have their birds and butterflies, so 



*' Life in rare and beautiful forms 



Is sporting amid tliose bowers of stone ;" 



for fish of various hues, red, blue, purple, green, and other 

 brilliant shades, keep constant play, appearing and disap- 

 pearing among the branches. 



These fields of growing coral spread over submarine lands, 

 such as the shores of islands and continents, where the depth 

 is not greater than their habits require, just as vegetation ex- 

 tends itself through regions that are congenial. The germ 

 or ovule, which, when first produced, swims free, finds after- 

 wards a point of rock or dead coral to plant itself upon, and 

 thence springs the tree, or some other form of coral growth. 



The analogy to vegetation does not stop here. It is well 

 known that the debris of the forest, decaying leaves and 

 stems, and animal remains, add to the soil ; and that accu- 

 mulations of this kind are ceaselessly in progress ; that by 

 this means, in the luxuriant swamp, deep beds of peaty earth 

 are formed. So it is in the coral mead. Accumulations of 

 fragments and sand from the coral zoophytes, and of shells 

 and other relics of organic life are in constant progress : and 

 thus a bed of coral debris is formed and compacted. There is 

 this diff^erence, that a large part of the vegetable material 

 consists of elements which escape as gases in decomposition, 



