THE BUILDING OF THE LAND 3 



and are of coral formation. The lower islands are 

 of oolitic limestone and many of them run almost 

 directly across the axis of the chain. If the visitor 

 is a botanist he will find that the flora of the south- 

 east mainland differs decidedly from that of the 

 upper islands, although but a few miles distant, 

 and also that many plants of the upper chain are 

 not found on the lower group. 



The observer will also notice that almost every- 

 where along both coasts of the State and separated 

 from the mainland shore by narrow sounds there 

 is a series of long islands or peninsulas, generally 

 parallel with the shore, composed of sand and often 

 covered with vegetation. He will find that in the 

 lower part of Florida the protected shores of these 

 islands and of the mainland are usually bordered 

 by a dense growth of mangroves standing high 

 on stilted roots and often reaching well out into 

 the water. These trees help in a wonderful manner 

 to build up the land. 



If our visitor be a Nature lover he will ask why 

 is this great area so low and flat ; why are there no 

 stream valleys; why should the State be pine 

 covered with only here and there an island-like 

 hammock? Why so sandy, and whence came 



