ACCOUNT GIVEN BY BOITEL. 45 



plant with trees the Dune, will cost, at least, 500 francs per hectare. 

 This outlay ceases, however, to appear exorbitant when we consider 

 the protection which it provides. Almost the whole is laid out on 

 the erection and keeping up of palisades, and chiefly in the transport 

 from long distances, across moving sands of great depth, of the 

 required planks and faggots of brushwood." 



And it is stated by him that one effect of the reboisement — or, as 

 that word is scarcely applicable though the word employed, the 

 growth of the pineries — has the effect of drying up the stagnant 

 water in the lettes, " either,'' says Boitel, " by the evaporation con- 

 nected with vegetation, or more likely by the formation of mould, by 

 which the moisture is absorbed and retained, or by some unknown 

 operation." 



Such artificial sowing as has been described may be necessary in 

 taking in new ground, and it is practised elsewhere; but in the 

 Landes natural reproduction is sufficient to maintain the pignadas. 



" The pine," says Boitel," produces cones with impricated scales. 

 These scales, compactly arranged, varnished, and of bone-like consis- 

 tence, form a covering for the seed which may seem to be indestruc- 

 tible ; but by an organisation which calls forth manifested admira- 

 tion of the Providence, the scales which man could scarcely break by 

 artificial means open as if by enchantment when they attain a 

 certain temperature. 



" The heat in dilating them, causing them to bend backward, 

 separates them one from another, and in the new position thus taken 

 they offer an easy exit to the winged seed which they had previously 

 held imprisoned. 



"Let it be borne in mind that the cones remain attached to the tree 

 beyond the period of their maturity, that they are persistent and 

 pendent on their peduncle, or stalk, and it will be seen that they are in 

 a position admirably adapted for favouring the escape of the seed, and 

 this, yielding to its weight, detaches itself freely from the opened 

 out scale, and immediately by its wings it comes, under the disseminat- 

 ing influence of the winds. 



" The seeds thus sown germinate under the shade of the old trees, 

 and form a young repeuplemeni, or new generation of trees, to take 

 the place of the old when they shall pass away ; and destined to be 

 productive when the time shall come for the final and complete 

 exploitation of the older trees reserved for this purpose. 



" These natural sowings are, so to speak, the only means of produo- 



