270 RAMBLES OF A NATURALIST. 



a cheerful country house with an adjoining farm and 

 gardens, enclosed between a line of low hillocks. 

 These hillocks, which are every year being more and 

 more levelled by the action of the plough, are all 

 that now remains of Fort Louis, which according to 

 the prediction was to have swallowed up the city, 

 and it is only with difficulty that the eye can trace 

 by a few irregularities of the soil, the plan of the 

 glacis and the lines of its trenches. The dyke has 

 been better preserved ; for although the winds and 

 the waves have demolished the summit and rendered 

 the sides less steep, its foundation stones may still be 

 seen at low water, running out from the shore in a 

 long black line, which still seems as if it would bar 

 the entrance to the harbour. 



The neap tides, which had opposed so decided an 

 obstacle to my zoological excursions, did not, how- 

 ever, prevent me from traversing the coast day by 

 day in order to form some idea of my prospects of 

 success, and certainly my first explorations inspired 

 me with very serious apprehensions on this subject. 



My preceding researches had shown me that lime- 

 stone is infinitely less rich in marine animals than 

 schists and granites. The greater softness of this 

 stone prevents it from resisting a purely mechanical 

 shock, even when it occurs in compact masses. Be- 

 sides this, the chemical composition of limestone 

 enables the water to dissolve a portion of it, which 

 although inconsiderable is not the less appreciable. 

 On this account the Alga? and Fuci, which on the 

 shores of Brittany cover the granite with detached 

 clumps or extended sheets of verdure, cannot attach 



