5CXX11 



I'ULVl'K.S.— TIIK COU.U,. 



corrcspontliiig part of tlie axis ceases to develop. 

 Betweea it and tlie polypier an inliniate relation, 

 llierefoie, exists. Examine it closely, and you will find 

 it to consist of tUiee principal elements— a common 

 tissue, certain sj'iculcv, and divers vessels. 



Of the tissue it is only necessary to tay that it 

 resembles a glossy, transparent mombraue. It is cel- 

 lular and contractile. 



The Rpiculae are minute calcareous concretions, 

 more or less elongated, covered with knotted juints 

 which bristle with spines, and of a regular determinate 

 form. They possess the power of refracting light with 

 intense vividness, and their colour is that of the coral, 

 though less intense on account of their thinncs.s. They 

 are uniformlj' distributed throughout the fleshy sub- 

 Bianoe we have beeu describing, and communicate to 

 the coral its peculiar and much-prized colour. 



The vessels form a close coujpact netwoil;, which 

 extends aud repeats itself in the thickness of the crust. 

 They are of two kinds : while some of tolerable size 

 are embedded in the axis and arranged in parallel 

 layers, the others are more regular and much siualler. 

 This vascular network has a direct and iiuportant con- 

 nection with the polypes, on the one hand, and with 

 the axis or central substance, on the other. It also 

 maintains a close communication with the general 

 cavity of the animal's body by every channel which 

 approaches it, while the two ranges of network stretch 

 towards each other a great number of anastomosing 

 processes. 



How do the corals feed ? The alimentary fluids are 

 conveyed to the animalcules which inhabit the various 

 cavities of the polypier by delicate intermediary canals. 

 The alimentary fluids elaborated by the Polypes them- 

 selves, flow into the branches of the secondary and 

 irregular network system, and so pass to the great 

 parallel tubes that stretch from one extremity of 

 the organism to the other, and thus supply the entire 

 community. 



When one end of a branch of living coral is rup- 

 tured or broken, a whitish liquid immediately gushes 

 from the wound, which mingles with the water, and is 

 exactly like milk. This is the fluid aliment which has 

 escaped from its containing vessel, charged with the 

 debris of the organism.* 



" What occurs," says a modern writer, " when the 

 bud produces new polxpes? It is only in round well- 

 developed animals, aud particularly those with branch- 

 ing extremities, that this phenomenon occurs. The 

 new organisms resemble little white points pierced 

 witli a central orifice. AVith the help of the micro- 

 scope, we discover this white point to be starred with 

 radiating white lines, the edge of the orifice bearing 

 eight distinctly traced indentations. All these organs 

 are gradually enlarged until the young animal has 

 attained the shrub-like or branched aspect belonging 

 to, and characteristic of, the compound poly|)e or poly- 

 pier. Tlie tube is branching, and the orifices from 

 which the polypes expand dilate into cup-like cells." 



True corals are divided into the Melitcs and the 

 J.^is; whose ramifications are articulated, and whose 

 pol_\ pes possess six tontacula instead of eight. These 

 * I'iguier, Tlie Occau 'Woild. 



tentacuUi are entire and unbroken. In the Melitcs 

 the axes are knotted or jointed at intervals, and 

 covered with a permanent adhering crust ; in the Jsis, 

 they are etrangles, and clotlied in a loose decaying 

 envelope. The tissue of tlie former is stony and 

 homogeneous; that of the latter, is composed of two 

 distinct substances ; their spicula; are haiiy and black- 

 ish ; their articulations striated and calcareous. 



The stem of the Isis is often used in commerce for 

 white coral; but the siruclure of the two is so dilfeient 

 tliat, with a glass, they may readily be distinguished. 



Kach coral, true or false, is a distinct workshop 

 or laboratory of tiny labourers, skilful, numerous, and 

 ever active ; a wonderful workshop, where they manu- 

 facture, at one and the same time, the original 

 material, horn or maible, which ia indispensable to 

 them, and the graceful products, stems or branches, 

 which are their characteristic products. 



From these explanations of the nature of coral, si_\8 

 Fredol, it is evident that these polypes more nearly 

 resemble plants than animals. It is for this reason 

 that they are frequently included under the designation 

 we have already used. Zoophytes, or animal plants — 

 a designation which is extended to a great number of 

 marine Invcrtebrata. 



The points of resemblance between these animals 

 and the members of the vegetable kingdom are as 

 curious as they are interesting. To the unscientific 

 eye they might reasonably pass for petrified plants. 

 Like vegetables they have a stem, branches, and twigs 

 — all covered with a veritable bark. Their axes are 

 horny or calcareous, while those of vegetables are woody 

 or herbaceous. In both the tissue is of greater or 

 lesser solidity, striated, channelled, twisted, and com- 

 posed of concentric layers. Moreover, the animal 

 bark is spongy, and more or less tender, like the 

 vegetable bark. 



The gems represent buds; the Polypes, flowers. 

 The filaments expand in rosettes like petals; they 

 form a living coralla, which alternately opens and shuts. 

 In the polypier, as in the vegetable, the elementary 

 individuals are situated at the extremities of the axes, 

 or on the sides, or, rather, are both terminal and lateral. 

 Finally, another point of resemblance is found in 

 their mode of reproduction. Both the coral and the 

 vegetable give birth to isolated organisms, eggs or 

 seeds, which detach themselves from the parent mass, 

 delvelop gradually, and produce a colony, whose mem- 

 bers remain adherent, and, in succession, other corals 

 and other vegetables, that is to say, other collective 

 beings. It is the synthesis which engenders analysis, 

 and the analysis wdiich reconstitutes the synthesis. 

 In plainer language, from the addition springs division, 

 and from the division again occurs addition. The 

 many produce the one, and the one, in its turn, produces 

 the many. 



Tlie coral of commerce, on^^ so highly valued by all 

 collectors of »«{(«, is, of course, the Polypier. It is a 

 cylindrical substance, much channelled on the surface; 

 the lines generally running parallel to the axis of the 

 cylinder, and the depressions corresponding to the 

 animal's body. Exaniiiic the transverse section of a 

 polypier, and you will find it regularly festooned on 



