346 



THE CIVIL ENGINEER AND ARCHITECTS JOURNAL. 



[October, 



vital action therefrom, as well as administering nourishment thereto, as it 

 consolidates by abstracting its food from the medium in which it moves, so 

 its lower portions gradually assimilate to the calcareous basis on which it is 

 placed, and new offshoots arise to vegetate in turn their fleet existence, until 

 they enter the second stage, and eventually into the fossil kiDgdom. It is 

 upon the gelatinous viscid matter covering the surface of corals and coral- 

 lines that the animals of the deep feed, it is to the vast plains covered with 

 half naked and naked polyps, that whales, turtles, and other species repair to 

 revel in abundance, cropping the surface, which is rapidly renewed again. 

 Mr. Darwin is decidedly m error when he talks of fishes browsing upon the 

 coral branches ; it is true that calcareous matter is often found in the sto- 

 mach of fishes, particularly those of the coral species, but it is equally true, 

 as previously observed, that many of the polyps, while in their soft state, 

 contain a great portion of calcareous matter, and to the continued increase of 

 this matter the coral owes its eventual solidity. On the other hand, the ge- 

 nerality of species while living, are filled with a milk-like fluid, fat, sharp, 

 and astringent, and in some of the Gorgonia in particular, so powerful are its 

 effects, as to draw blood when applied to the tongue, for while in the living 

 state a strong electric excitement is evident in the living system : it is also a 

 fact that minute or naked animalculae are seldom, if ever, found located on 

 the coral branches, the intruders being generally shell-bearing animals of 

 like constituents with themselves. And finally, months of observation among 

 the coral reefs have convinced the writer of this article that the delicate 

 brandies always remained uninjured by fishes, which feed upon them as ants 

 feed upon the aphides, robbing them of their sweets alone, and leaving the 

 body uninjured. 



Lythophyta, Tubipora, Millepora, Madrepora, and Fungosa, propagate 

 their kind through the means of their juices, which exuding from the parent 

 trunk, fall upon the surrounding soil, become attached thereto, and if cir- 

 cumstances be favourable, are speedily generated, being governed in their 

 first development by electro-chemical action, where light and heat are neces- 

 sary adjuncts ; in their increase, by the forces which govern vegetable bodies 

 in their multiplication of parts ; and, in their advance towards maturity, by 

 the laws of organic life as their organical structure becomes developed. Their 

 food is received through the cellular pores, and consists of water and the 

 atomic particles floating therein, which, received into the living system, 

 undergo chemical change, forming products similating with the organic 

 bod] . eventually converted into the milk-like fluid, which, like the sap of a 

 tree or the blood of an animal, pervades the whole system. From the deve- 

 lopment of the gemma or buds in many species to their full maturity of 

 growth, they exhibit all the phenomena of terre.-trial plants, being uniform 

 in their development, growth, and decay, and propagating by their seeds and 

 ci ttings. 



This similarity of action and organical arrangement would at once identify 

 them with the vegetable kingdom, was it not for the animal matter manifest 

 in all of them ; it is certain that they difler little from fucuses and confervas, 

 and like them are uniform in their growth, development, and decay ; we can 

 therefore only come to the conclusion that Life throughout nature is one, 

 although differing in degrees ; that by nature animal has no distinction above 

 Vegetable life, but acquires powers, under favourable circumstances, from the 

 superiority of its elastic compounds and peculiarity of its organic action, 

 which is not distinguishable in lower organizations: that when organic 

 is impeded by the rapid secretion of calcareous matters, the body or 

 form, unless under intense energy of light and heat, and other favourable 

 circumstances, is not enabled to pass the boundaries of simple organization, 

 such as distinguish vegetable bodies : and so far as respects the stony polyps, 

 the mixed qualities which compose the juices and the animal framework, as 

 lime, soda, magnesia, &c. are inimical to their attaining any considerable 

 size, or to the development of nerves, marking an advance in organic charac- 

 ter. As regards life, they may, therefore, be considered as one with the vege- 

 table kingdom, and that while the animal matter secreted by the functional 

 operations of life identifies them as belonging to the animal kingdom ; the ac- 

 life by which their animal matter, carbon, lime, ammonia, and other 

 compounds are produced, and the organs of reception, retention, and motive 

 power, by means of which they draw their nourishment from the medium in 

 which they live, as also the act of procreation by division of their parts, and 

 the ultimate development of peculiar form to a definite extent only, and the 



organical arrangement of the several compounds of which the body consists, 

 as strongly identify them with the vegetable kingdom. 



The colourless pellicle which distinguishes many species of the zoophyta 

 planta, and is also distinguishable in some of the stony species, is formed in 

 every individual of the vegetable kingdom ; the cellular texture is formed 

 from the membranous in like manner, varying in form in different genera and 

 species ; the ligneous fibre is substituted by the stony matter, which supports 

 and constitutes the solid part of the body, being also formed by a series of 

 depositions, which, after the body has attained maturity, gradually encroach 

 upon the vascular vessels, and, by arresting further circulation, destroy the 

 vital principle. In like manner with vegetables, many species are perma- 

 nently fixed upon bases, advancing in their growth towards the rays of the 

 sun in the direction of light and heat, and this vegetative process is mani- 

 fest, not only in the Zoophyta Planta, but also in numerous species secreting 

 lime, as sea ferns, sponges, madrepores and millepores. 



Many of the stony polyps, while in the living state, continue soft and 

 yielding to the touch, but as the sap vessels fill up, they gradually indurate, 

 and if this take place beneath the waters, they become converted into limestone 

 rock ; thus it is with the beautiful Meandrina spreading over its consolidated 

 bases in moss-like clumps : its external covering is exceedingly soft, similating 

 to the living sponge, and as it enlarges, so it enlarges on every side; its animal 

 matter is converted into a kind of bony substance, which is filled with living 

 juices passing to and fro through the whole system, until the entrance to the 

 cellular pores becoming filled up, the lower portion dies, but still remains 

 attached to the living body. 



The time that each species requires to perfect its growth is very variable, 

 necessarily depending upon latitude, dip, and inclination ; and again, upon 

 its preservation from those numerous accidents to which it is subject in com- 

 mon with all forms of life, sucli as local or general disturbance of the me- 

 dium in which it is placed, or the predatory warfare urged against it by 

 almost all the living species of the deep. An erroneous idea is entertained 

 by men of science, that the stony polyps are of exceeding slow growth, such 

 being the natural consequence of their consolidated nature; thus F,hrenberg 

 calculates that the specimens of Meandrina seen by him in the Red Sea were 

 at least 2000 years old ; but these, it would appear, were of the dead and not 

 of the living coral: and even if living, the calculation is ridiculous, for, in 

 fact, they attain a very great size in 20 years when uninterrupted in their 

 growth. In tropical regions, where they enjoy heat and quietude, their 

 growth is exceedingly rapid, rivalling, in this respect, terrestrial plants and 

 grasses ; but like the latter they are the food of myriads of creatures which 

 greedily crop off the flesh-like surface, and thus retard their growth. In the 

 lower depths and beneath temperate climes, like the leaves of the forest, they 

 die off annually, or, otherwise, their growth is retarded by adverse circum- 

 stances of low temperature and local disposition. Much also depends upon 

 their freedom from tidal disturbance, for the tender and delicate gemma or 

 buds of many species are easily washed away by the ocean tides, or destroyed 

 by the intrusion of sands, or other matters inimical to their freedom of action 

 or alien to their nature. 



Some idea of the time required to mature their growth, may be derived 

 from our knowledge of the growth of the white and red corals of commerce, 

 in the Mediterranean Sea. Marsigli informs us that the white coral of this 

 sea is most abundant in caverns to the south, and where the sea is smooth 

 and tranquil ; that it is seldom found in a western exposure, and never to 

 the north ; that when the caverns are despoiled of it, ten years are allow ed 

 by the fishers for its regeneration, and in this time it attains its extreme 

 height and thickness ; at greater depths it disappears. This is confirmed by 

 Spaglanzani, who says that in the neighbourhood of San Stephano the coral 

 does not attain half a foot in 10 years, and in proportion to its depth so it de- 

 teriorates in quality, and gradually disappears ; that the greater quantities 

 are at depths varying from 60 to 125 ft., and some fisheries are carried on to 

 the depth of 900 ft. ; at this latter depth it is said to require 40 years to at- 

 tain the same size which, at the depth of GO ft., it attains in 10 years. Ill all 

 parts of the ocean, local influences determine the time requisite for maturing 

 the coral. M. de Peysonnel found that the coral grows in different directions, 

 sometimes perpendicularly downwards, sometimes horizontally, and some- 

 times upwards, and in the caverns of the sea open to every exposure. La- 

 mouroux remarks. " we find some polypidoms placed always on the southern 



