rOI.YPES.— THE CORAL. 



esteemed for its vivid and dazzling colour. Tlje Italian 

 species is probably not inferior, but that of Barbary is 

 coarser and less brilliant. 



In commerce four kinds of coral are recognized, and 

 distingiiislied by somewhat fantastic designations, as, 

 1st, Foam of Blood; 2nd, Flower of Bloo(i ; 3rd, First 

 Blood ; 4th, Second Blood. Rose coral is very rare 

 and very dear. 



Bnt the labours of these curious animalcules are 

 productive of more important results than the mere 

 decoration of the persons of the wealthy and luxurious. 

 Those species which belong to the order Tubiporiiue 

 are tlie creators of the coral islands of Southern seas. 

 The manner in which they work is truly marvellous. 

 Their toil is slow, but it is continuous; for as fast as 

 one animalcule dies another takes its place. It is not 

 for themselves; they derive no advantage from their in- 

 dustry; they are simply fulfilling the functions imposed 

 upon them by Almighty power, and by building up 

 reefs and islands, which hereafter may be expanded 

 into continents, hastening the completion of the grand 

 scheme of creation. 



The examination of a coral reef is, therefore, a 

 peculiarly interesting study for the scientific observer. 

 When the sea has receded from it for some time it 

 becomes dry, and appears to be a compact rock, 

 exceedingly hard and ragged ; but as soon as the 

 waters return, and the tide washes over it, myriads of 

 corallines emerge from holes which were previously 

 invisible. They are of great variety of shape and size, 

 and in such prodigious numbers, that (says Basil Hall) 

 the entire surface of the rock seems alive and in 

 motion. A very common form is that of a star, with 

 arms from four to six inches long, which it moves about 

 with a rapid motion in all directions, probably in quest 

 of food. Captain Hall observed some of a very sluggish 

 disposition, so that they were frequently mistaken for 

 pieces of rock ; they are generally of a dark colour, and 

 trom four to five inches long, and two or three round. 

 When the rock, says our authority, was broken 

 from a spot near high-water mark, it was found to be 

 a hard solid stone ; but if an}' part were detaclied at a 

 level accessible to the tide 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 yellow, occasionally of a 

 blue colour; others resembled snails; others were not 

 unlike snails and worms in shape, but soft, and not 

 above twenty-four inches in length. The growth of 

 coral ceases when the worm which creates it ceases to 

 be exposed to the action of the tide. Thus a reef 

 rises in the form of a gigantic cauliflower till its sum- 

 mit has reached the level of the highest tides, above 

 which the worm has no power to carry its operations, 

 and the reef, consequently, no longer extends itself 

 upwards. The surrounding parts, however, advance 

 in succession until they reach the surface, where they 

 also must stop. Thus, as the level of the highest tide 

 is the eventual limit to every part of the reef, a hori- 

 zontal field comes to be formed coincident with that 

 plane, and perpendicular on every side. The reef, 

 however, continually increases, and, being prevented 

 Irom going higher, must extend itself laterally in all 



directions; and this growth being probably as rapid at 

 the upper edge as it is lower down, the steepness of 

 the face of the reef if preserved ; and it is this circum- 

 stance which renders the coral rocks so dangerous in 

 navigation. In the first place, they are seldom seen 

 above water; and in the next, their sides are so abrupt 

 that a ship's bows may strike against the rock before 

 any cliange of soundings indicates the approach of 

 danger.* 



A popular English poet has described the modus 

 operandi of the coralline in eloquent and yet scientifi- 

 cally accurate terms : — 



"iMillions of millions tlms, from age to ngp, 

 With simplest skill, and toil unwejuiable, 

 No moment and no movement unimproved. 

 Laid line on line, on terrace terrace spread; 

 To swell the heightening, Irightenint;, gradual mound, 

 By marvellous structure climbing towards the day. 

 Eacli wrouglit 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, 

 \\*ornis did. 



I saw the living pile ascend. 

 The mausoleum of its arctiitects, 

 Still dying upwards as their labours closed : 

 Slime the material, but the sliine was turn'd 

 To adumant, by their petrific touch ; 

 Frail were their frames, ephemeral their lives, 

 Their masonry imperlsliahle. 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 

 Delivered ocean of that monstrous birth — 

 A coral island stretching east and west." | 



In the Pacific and Indian oceans are fuur different 

 kinds of coral formations, all the lesults of the labouis 

 of these minute organic beings. Dr. Darwin de- 

 scribes them as Lagoon islands, or Atolls ; Encircling 

 reefs ; Barrier reefs ; and Coral fringes. The Atol's 

 are only found in the Pacific and Indian oceans; the 

 others in every Tropical sea. 



An Atoll is a ring of coral which incloses a 

 lagoon or circular tract of ocean in its centre. 

 That part of the ring which rises above the water is 

 generally about a quarter of a mile in breadth — 

 frequently, much less — and seldom rises higher than 

 from six to twelve feet above the water. Conse- 

 quently, they are not discernible even at a small 

 distance, uidess they happen to be covered with a 

 leafy growth of the screw-pine, palm, and cocoa-nut. 

 On the outer side this coral circle shelves down fur 

 some one hundred or two hundred yards, and the sea 

 gradually deepens to twenty-five fathoms ; beyond 

 which it plunges straight down into the unfathomable 

 depths of ocean, like the precipitous sides of an abrn]it 

 volcanic cone. Even at the distance of some hundred 

 yards, says Mrs. Somerville, no bottom has been found 

 with a sounding-line one mile and a half in length. 



* Captain Basil Hall, Narrative of a Voyage to Loo Choo, &c. 

 f James Montgomery, The Pelican Island. 



