28 Submarine Forest in Largo Bay, 



If the opening of the connecting entrance of the Mediterra- 

 nean with the Atlantic, at the Straits of Gibraltar, were by any 

 means enlarged, high and low water marks, in the former, 

 would be removed to a greater distance from each other, and 

 places would be periodically covered by the one and uncovered 

 by the other, which, at present, may be considered as protected, 

 in consequence of the imperfect communication with the ocean 

 diminishing the oscillations of the tidal wave. Similar occur- 

 rences must have frequently taken place in the creeks and 

 estuaries of our own shores. 



If the opening of the Red Sea into the Arabian Sea, by the 

 Straits of Babelmandel, became more contracted, by the in- 

 crease of coral reefs or sand-banks, the tidal waves of that gulf 

 would experience a corresponding diminution, and instead of 

 rising at high water, two or three feet above the mean level, 

 they would become confined in their oscillations to a few inches, 

 as in the Mediterranean at present. If the elevation of the 

 mean level of the tide, at high water, became thus diminished, 

 pools formerly filled with sea water and occupied by marine 

 plants, might pass into fresh-water lakes, and a layer of peat 

 might be formed of plants common to such a situation, covering 

 or intermixed with the remains of the anterior marine vegeta- 

 tion. Such changes seem on the continent to have taken place 

 at Linum, near Berlin, and in the vicinity of Drontheim. And 

 there is some reason to suppose that similar changes had 

 occurred at the Parret, in Somersetshire, where leaves of a 

 zostera have been found, according to the observations of 

 Mr. Horner. 



But these changes which may take place in the level of high 

 water, though they may afford an explanation of submarine 

 forests situate above the mean level of the sea, furnish no evi- 

 dence applicable to such as present themselves in an inferior 

 position, or below the mean level of the sea. The submarine 

 forest described by Dr. Correa de Serra, is stated as extending 

 to the lowest ebbs in the year, or probably eight or nine feet 

 below the mean level of the sea. The Somerset submarine 

 forest is situate '* considerably below the level of the sea, and 

 now only to be seen at low water," Both the examples in Fife 

 likewise extend below the mean level of the sea. 



According to the views which I have adopted and illustrated 



