176 AGE OF CORAL REEFS. 
This demands some explanation, since I have 
already said that no Coral growth can continue 
after it has reached the line of high water. But 
PENINSULA 
OF 
2 FLORIDA. 
we have not finished the history of a Coral wall, 
when we have followed it to the surface of the 
ocean. It is true that its normal growth ceases 
there, but already a process of partial decay has 
begun that insures its further increase. Here, 
as elsewhere, destruction and construction go 
hand in hand, and the materials broken or 
