ALONG THE STREAM 237 



by the streams during high water to form exten- 

 sive mud flats at their mouths. Muck and peat 

 may be added by the rank vegetation which 

 springs up on it. A bar frequently forms just 

 outside the debouchure. I believe these bars are 

 formed in quite the same way that are the parallel 

 islands and peninsulas along the coasts — that is, 

 by two opposing currents. 



A trip up any of these streams reveals much of 

 beauty and interest. Having crossed the outer 

 bar, where the water may be so shallow that it is 

 difficult to pass with a skiff, one at once finds a 

 depth of from six to ten feet, and this depth may 

 be carried for a long distance up the estuary. Gen- 

 erally the bottom is of solid limestone, with an 

 occasional mud bar. The lower course of the 

 stream is likely tortuous and bordered with a 

 dense growth of mangroves and other littoral 

 trees. These are often large and tall, their tops 

 completely arching the estuary. The low shores 

 are a tangle of roots, and the mud is thickly stud- 

 ded with the quill-like pneumatophores of the 

 white and black mangrove. In this complex will 

 be found two species of giant Acrostichums, half 

 aquatic ferns which are equally at home in brack- 



