460 BOTANICAL GAZETTE [DECEMBER 
In sections 2 and 3 below we will inquire further into the reliability 
of salt peat below sea-level as a proof of recent subsidence. 
2. Phenomena produced by a local rise in the high tide level 
It has.seemed necessary to treat the fictitious appearances of 
changes of level as fully as has been done above, because of the 
widespread belief in the value of such phenomena as proofs of 
coastal subsidence. The local fluctuations of high tide level, now 

= 
~ 
~, 94 
~~.” 
~~ 




Fic. 6.—Bay separated from the open sea by a barrier beach 
to be discussed, are of much greater importance, but may be 
explained in a shorter space. The principle of these fluctuations 
will be readily apparent from figs. 6-8. 
On a tidal coast, if we have a bay like that shown in fig. 6, 
almost separated from the open sea by a barrier beach, but con- 
nected with it by a narrow tidal inlet, the waters of the rising 
tide in the sea will pass through the tidal inlet with so much diffi- 
culty that the surface of the bay will rise much more slowly than 
the surface of the sea. When the tide in the sea has reached its 
