154 



HOW THE KEYS MAY GROW TO THE MAIN-LAND. 



inetto, the rotting logs of which gradually make a wide extent of solid 

 and fertile ground. 



Discovering this, Indians would get into the habit of landing there to 

 open and feast upon oysters, clams, and concha, and from the debris of 

 these feasts would accumulate mounds or ridges hundreds of yards long 

 and many feet in height. When the white man comes along he discovers 

 the largest trees and most luxuriant undergrowth upon these mounds of 

 shells. Recognizing the excellence of the soil, it is there he places his 

 house and plants his farm. The old oyster- bar becomes an 

 "island" with a name on the maps. 



Now the formation of keys j List in this way has long been 

 going on, and clusters of them abound all the way from Appa- 

 achicola to Key West. A group of mangrove islands, near 

 such a coast as Florida's, acts like the interlacing roots on a 

 single key ; the currents are stopped, tides slackened, drifted 

 matter and sand deposited, and great shoals, mud -fiats, or 

 sand-bars result. Given such an archipelagic condition, a 

 straight sand-bar, or outer beach, is a natural sequence, and 

 this, once formed, contributes still more to the shoaling 

 of the channels inside, until they eventually become al- 

 most or quite obliterated, because many of the islands 

 join together and finally unite with the main-land. 



But, as I have said, this is wholly the work of an- 

 imal life. Not until the oysters and their neigh- 

 _ ; -^ bors have really formed a "key" do the man- 



groves, with their train of aids, take 

 up the work ; and not until this 



AT THE MARGIN OF A MANGItOVE KEY. 



