FORMATION OF CORAL REEFS. 163 



lime does not belong either to the naturalist or 

 the geologist, its suggestion reminds us that the 

 time has come when all the sciences and their 

 results are so intimately connected that no one 

 can be carried on independently of the others. 

 Since the study of the rocks has revealed a 

 crowded life whose records are hoarded within 

 them, the work of the geologist and the natural- 

 ist has become one and the same, and at that 

 border-land where the first crust of the earth was 

 condensed out of the igneous mass of materials 

 which formed its earliest condition, their investi- 

 gation mingles with that of the astronomer, and 

 we cannot trace the limestone in a little Coral 

 without going back to the creation of our solar 

 system, when the worlds that compose it were 

 thrown off from a central mass in a gaseous 

 condition. 



When the Coral has become in this way per- 

 meated with lime, all parts of the body are 

 rigid, with the exception of the upper margin, 

 the stomach, and the tentacles. The tentacles 

 are soft and waving, projected or drawn in at 

 will ; they retain their flexible character through 

 life, and decompose when the animal dies. For 

 this reason the dried specimens of Corals preserved 

 in museums do not give us the least idea of the 

 living Corals, in which every one of the millions 

 of beings composing such a community is crowned 



