ENCROACHMENTS OF THE DUNES. 37 



hills are separated from one another by valleys, locally named laites 

 or lettes. These valleys, where the pluvial waters flow and accumu- 

 late, exhibit a striking contrast, in their freshly- blooming verdure, to 

 the naked, barren Dunes. The general aspect of the landscape may, 

 therefore, be compared to that of the ocean. There is the same 

 broken surface, the same extent of undulation, the billows of sand 

 being upheaved by the wind like the billows of the sea, and sharing 

 in their mobility. You must see, says a writer, in order to form an 

 idea of those colossal masses of fine sand, which the wind incessantly 

 skims, and which travel in this way towards the inland country : 

 yon must see their contours so softened that they look like mountains 

 of plaster of Paris polished by the workman's hand, and their surface 

 so mobile that a little insect leaves upon it a conspicuous track ; 

 their slopes, at every degree of inclination ; their everlasting steri- 

 litynot a blade of grass, not an atom of vegetation ; their solitude, 

 less imposing than that of the mountains, but still of a truly savage 

 character. You must see, from the summit of one of these ridges, 

 the ocean on your right hand, and on your left the extensive lakes 

 which border the littoral ; and, in the midst of this tumultuous sea of 

 tawny sand, green grassy valleys, rich and fertile pastures, smiling 

 oases of verdure, where herds of horses graze, and cows half-wild, 

 guarded by shepherds scarcely less wild than they.* 



The marked characteristic of the Dunes, as we have already said, 

 is their mobility, which renders them a constant menace for the 

 neighbouring populations. To the wind which creates them they 

 owe their frequent changes and their inland movement. While the 

 sea eats into the coast, assisted by the breezes which gradually sweep 

 clear the ground before it, the Dunes extend, and drive before them 

 the shallow lakes : these in their turn encroach upon the Landes, and 

 until now man has been constrained to recoil, step by step, before his 

 threefold enemy. It is in this phenomenon, rather than in the 

 ungrateful soil of the Landes, that we must seek the cause of the 

 curse which has seemed so long to rest upon this country-side. You 

 * SI. Perris, in " Memoires de I'Academie de Lyon." 



