266 ELEMENTS OF SYLVICULTUEE. 



draw the .reader's attention to a disease which has 

 been observed in some of these forests. Not unfre- 

 quently a pine withers and dies. Starting from the 

 pine as centre, the disease spreads all round over a 

 circular area of an ever-increasing radius. I was 

 not able to investigate its cause. In la Sologne it 

 had been pointed out to me by persons who ascribed 

 it to causes more or less imaginary. May not the 

 disease be traced to a fungus which attacks the 

 woody tissue itself? The circular area over which 

 it propagates itself leads to this supposition, which 

 is strengthened by the means adopted to combat it. 

 In the department of the Landes the progress of the 

 disease is effectually stopped by digging a trench 

 twenty- seven inches deep all round the portion of 

 the forest so attacked. 



NOTE. [Trs.] TheBalticCoastislinedwithdunesin 

 every respect similar to those of the Coast of Gascony. 

 According to Oberforster Gumtau, of Stettin, works 

 for fixing these moving sand-hills were begun as 

 early as the fourteenth century. Neglected or even 

 totally abandoned, especially during the Thirty 

 Years' War, they have just been resumed in order to 

 protect the country in the interior. The littoral or 

 anterior dune is principally fixed with plants possess- 

 ing spreading roots and sending up suckers, such as 

 ihePsamma arenaria, &c., grasses which are planted 

 in square sods of four metres side in the form of the 

 squares of a chess-board ; so that the lines are 

 respectively perpendicular and parallel to the direc- 

 tion of prevailing winds (N.W.). As to the inside 



