104 Description of the Landes of Acquitania. 
’ The numerical proportions of these plants, as drawn up from the 
tables given by C. D’Orbigny, are as follows: 
Ulve. Fuci. Ceramia. Diatome. Zostere. 
Ist Zone, 4 0 
2d Do. 14 15 9 2 2 
3d Do. 6 13 12 0 0 
4th Do. 6 13 4 0 0 
5th Do. 0 6 4 0 0 
6th Do. 1? 5 0 0 0 
The first zone extends from a French foot below the line of high 
water to a depth of 20 feet. The second zone extends from 5 to 
30 feet in depth. The third from 15 to 35 feet. The fourth from 
20 to 40 feet. The fifth from 30 to 60 feet. And lastly, the sixth 
zone from 40 to 100 feet, beyond which, in these seas, there is no 
vegetation. 
‘When the sands attain little elevation in the neighbourhood of 
the sea, no plants occur for some hundred yards beyond the line of 
high water. When, however, sand-hills succeed, the vallies at 
their base will present the vegetation of the downs where most 
barren. 
Sometimes a range of hills, as at the entrance of the basin of Ar- 
cachon, runs in a direction nearly at right angles to that of the 
shore, and such an arrangement is accompanied with extensive late- 
ral plains, sometimes only a few feet elevated above the level of the 
sea. The reed of the sands forms the characteristic vegetation of 
these tracts, whose appearance is moreover diversified by stray plants 
of a few vagabond species ; among them Cucubalus fabarius, most 
abundant among the new ly formed plantations of fir trees, Salsola 
Kali, S. Tragus, S. Soda, Polygonum maritimum, Elymus arena- 
rius, Chenopodium maritimum, Crithmum maritimum, Agrostis 
stolonifere, Arenaria peploides, A. rubra, Reseda sesamoides, Atri- 
plex portulacoides, Eryngium marjtimum. 
The lofty range of sand-hills which border the coast, are general- 
ly entirely naked, nor is their barrenness relieved by a single moss, 
or the green blade of a grass. 
In the plains which extend themselves at the base of most longi-' 
tudinal vallies, the means of fettering down these sands are general- 
ly put in force ; and in consequence the fir tree, and other ever- 
greens, rise up the acclivities of succeeding ranges, enlivened by 
numerous flowering leguminose, composite, ” &e. 
On these spots we particularly remarked the Heliotropium euro- 
peum, Athanasia maritima, Gnaphalium Stoechas, (about the lat- 
ter end of September, this beautiful plant gilds the southern aspect 
of many downs,) G. arenarium, Carex arenaria, Antirrhinum glau- 
cum, Cheiranthus maritimus, Daphne enidium, Statice limonium, 
S. Armeria, Gentiana maritima, Onosma echioides, &e. 
The vallies contained between the ranges, generally called Létes 
or Lesques, when covered with brushwood : are denominated Barthes. 
Sometimes these vallies are moist and marshy, at other times, the 
presence of fresh water is scarcely detected by the slight moisture 
