382 PHYSICAL GEOGRAPHY. 



" Millions of millions thus, from age to age, 

 With simplest skill, and toil unweariahle, 

 No moment and no movement unimproved, 

 Laid line on line, on terrace terrace spread, 

 To swell the heightening, brightening gradual mound, 

 By marvellous structure climbing towards the day. 

 Each wrought alone, yet all together wrought, 

 Unconscious, not unworthy, instruments, 

 By which a hand invisible was rearing 

 A new creation in the secret deep. 

 Omnipotence wrought in them, with them, by them ; 

 Hence what Omnipotence alone could do 

 Worms did. I saw the living pile ascend, 

 The mausoleum of its architects, 

 Still dying upwards as their labours closed : 

 Slime the material, but the slime was turn'd 

 To adamant, by their petrific touch ; 

 Frail were their frames, ephemeral their lives. 

 Their masonry imperishable. All 

 Life's needful functions, food, exertion, rest, 

 By nice economy of Providence 

 Were overruled to carry on the process 

 Which out of water brought forth solid rock. 



" Atom by atom thus the burthen grew, 

 Even like an infant in the womb, till Time 

 Deliver'd ocean of that monstrous birth 

 A coral island stretching east and west." 



Nothing more perfectly demonstrates the power of Nature to effect her vast designs 

 through apparently feeble and inefficient agents, than the coral formations. It requires, 

 indeed, ocular proof of the labours of the madrepores, to credit what stupendous sub- 

 marine reefs and islands, many miles in compass, are indebted for at least a great part of 

 their structure to the secretory economy of these minute artificers. 



The coral insects are abundant in the Mediterranean, where corallines of beautiful 

 forms and colours are produced ; but it is in the Pacific Ocean and its branches that these 

 tiny workmen are effecting those mighty changes which far exceed the most remarkable 

 labours of man. Interesting details have been furnished by many navigators respecting 

 these formations. They attracted the attention of Captain Hall in the seas around Loo 

 Choo, where the zoophytes belonging to the genera Astrea are most common, who re- 

 marks : " The examination of a coral reef, during the different stages of one tide, is par- 

 ticularly interesting. When the sea has left it for some time, it becomes dry, and appears 

 to be a compact rock, exceedingly hard and ragged ; but no sooner does the tide rise 

 again, and the waves begin to wash over it, than millions of coral worms protrude them- 

 selves from holes on the surface which were before quite invisible. These animals are 

 of a great variety of shapes and sizes, and in such prodigious numbers, that in a short 

 time the whole surface of the rock appears to be alive and in motion. The most common 

 of the worms at Loo Choo was in the form of a star, with arms from four to six inches 

 long, which it moved about with a rapid motion in all directions, probably in search of 

 food. Others were so sluggish, that they were often mistaken for pieces of the rock : 

 these were generally of a dark colour, and from four to five inches long and two or three 

 round. When the rock was broken from a spot near the level of high water, it was found 

 to be a hard solid stone ; but if any part of it were detached at a level to which the tide 

 reached every day, it was discovered to be full of worms of all different lengths and 

 colours, some being as fine as a thread and several feet long, generally of a very bright 



