22 IN LOWER FLORIDA IVILDS 



to the level of an ordinary high tide, while these 

 elongated bars are generally considerably higher. 



It seems more probable that these peculiar forma- 

 tions are caused by the action of the ordinary tides 

 aided by occasional storms which sweep in upon 

 the shore. Wherever a sandy sea bottom slopes 

 very gradually from the beach the waves stir up 

 the shifting sand for a long way off shore espe- 

 cially when strong tides are coming in or when 

 high winds blow towards the shore. This dis- 

 turbance of the water, — the ground swell, sweeps 

 up the sediment and loose sand at a depth of 

 several fathoms and often from a distance of some 

 miles out. After severe storms during which the 

 wind has blown towards the land, immense num- 

 bers of fish living in water of considerable depth 

 are occasionally cast upon the beach, their gills 

 choked with sand and mud. The water has been 

 so greatly disturbed they have perforce breathed 

 in the silt which they could not eject and have 

 literally drowned. 



As the shore is neared and the water becomes 

 more shallow its landward movement is accel- 

 erated, so that in some places and under certain 

 conditions it rushes in with considerable speed. 



