COKAL REEFS. 363 



which renders them the artificers of mineral masses and new 

 lands amidst the ocean, fitted eventually to become the abode 

 of man. The soft pulp of the coral animal secretes, or other- 

 wise elaborates, a stony nucleus ; the aggregation of which 

 matter, by the conjoint working of myriads of these little 

 creatures, and the accumulated and superimposed labours of 

 different species and successive generations, produces these 

 wonderful results : c admiranda, levium spectacula rerum,' 

 as they may well be termed, looking at the relation between 

 the agent and the magnitude of the work accomplished. 



In a later part of this article we shall have to refer again 



to this topic, as connected with the theory of coral formations 



and their relation to other great physical phenomena of the 



globe. Meanwhile we will merely remark, that the whole 



course of modern science tends to disclose facts analogous to 



those just mentioned. We everywhere see the wonderful 



agency of the organic life of former ages, in forming the 



material and determining the structure of the great masses 



which compose the crust of the earth ; as well as in producing 



other phenomena, apparently the most alien from such origin. 



Where formerly brute matter alone was seen or suspected, 



the eye of the microscope now shows the innumerable relics 



of living beings, the artificers of the very mass which thus 



entombs them. The flint nodules of chalk rocks, the hard 



Tripoli slate, even certain varieties of the noble opal, are 



composed, in part or wholly, of the siliceous cases of fossil 



infusoria. The sand which sometimes falls on ships far 



distant from the coast the mud which lies in the estuaries 



of rivers even the layers of ashes and pumice which cover 



the edifices of Pompeii give the same remarkable result. 



We look backwards through these ages of organic life on the 



surface of the earth ; and in the very minuteness of forms 



and species we find reason why they should have been thus 



readily aggregated into dense masses, concealing to common 



