GENEEAL IDEAS. 11 



and this is condensed into fog or hoar-frost as soon 

 as the sun goes down. The trees are not safe 

 against this danger until they have outgrown the 

 usual height of the fogs, i.e., six to twelve feet. 



The peculiar characters of each aspect may be 

 modified by local conditions ; in a valley an out- 

 jutting spur will change the original direction of the 

 winds ; on the Mediterranean, along the coast of 

 Eousillon, the strongest winds come from the east, 

 and bring moisture, &c. Again, elevation diminishes 

 the effect of aspect, and towards the limit of forest 

 vegetation, the difference between a northern and 

 southern aspect is no longer sensible, growth is 

 very slow, and the density of the wood small. 

 Lastly, shelter on this or that side further changes 

 the general effect of aspect. 



CLASSIFICATION OF CLIMATES. In order that we 

 may have precise terms at our disposal, the general 

 climate of France has been divided into the follow- 

 ing : 



Hot climate ; in which the cork, holm, and 

 kermes oaks, and the stone and Aleppo pines are 

 indigenous. 



Mild climate ; characterized by the cluster pine ; 

 the two large oaks bear seed in this climate almost 

 every year. 



Temperate climate ; the two large oaks, the horn- 

 beam and the beech are here very common ; but 

 acorns and beechnuts fall only every four, six, or 

 even eight years. 



Cold climate ; here the beech with the silver fir and 

 the Scotch pine constitute the large bulk of the forest. 



