174 FORMATION OF CORAL REEFS. 
these, there are certain plants, limestone Alge, Be 
— Corallines, as they are called,—which have __ 
their share also in the work. ‘a 
I had intended to give some account of the 
Coral Reefs of Florida, and to show what bear- 
ing they have upon the question of time and 
the permanence of Species; but this cursory 
sketch of Coral Reefs im general has grown to 
such dimensions that I must reserve a more 
particular account of the Florida Reefs and Keys 
for a future article. : 
