DEAD PRODUCTS OF TREES. 169 



the summer sun on the soil below them, they, on the other hand, 

 prevent the escape of heat from that soil in winter, and, conse- 

 quently, in cold chmates, even when the ground is not covered 

 by a protecting mantle of snow, the earth does not freeze to as 

 great a depth in the wood as in the open field. 



In the primitive forest the surface of the ground is so encum- 

 bered (often, indeed, half-covered) with trunks and branches of 

 fallen trees, that there sometimes seems to be as much wood pros- 

 trate as growing, and the necessity of cHmbing over, or creeping 

 under, the fallen trees, is the greatest difficulty in forest travel- 

 Kng. These decayed or wind-fallen trees intercept the water of 

 precipitation and convert the surface of the ground almost, some- 

 times altogether, into a bog.* The settler, for convenience, espe- 

 cially for cutting roads and paths, di'ags out these trunks, which he 

 uses for firewood and other pm'poses, thereby at the same time 

 partially draining the wood. A few years sufiice to get rid of this 

 material and convert a large area to the condition described above. 

 The wood, though still native and self-propagating, soon acquires, 

 to some extent, the character of an artificial forest. This process 

 was gone through with long ago in most European countries, so 

 that there is scarcely any truly original forest left in Central or 

 "Western Europe, in the condition in which Nature would have 

 placed it. An experienced eye at once recognizes a modern 

 wood as, in part at least, man's work. Especially is this the case 

 in Tyrol and the other Southern Austrian provinces, occupied, as 

 existing arcliitectural remains still show, and at least partly cleared, 

 hundreds, if not thousands of years ago. The woods have since 

 grown up again, but always under Government supervision. The 

 valley of the Drave, for instance, had, anciently, large towns and 

 of course adjacent fields, but the country is now almost com- 

 pletely wooded, and it is only since the opening of the railroad 

 through the Pusterthal and thence to Austrian and Itahan mar- 

 kets, that these new forests have been a little broken. Many in- 

 roads have now been made upon them for the sake of the timber, 

 and slides and torrents have already begun their ravages. But 

 not only do these forests differ from native woods in their general 



* See Milton and Cheadle's Travels, also Desor. 

 8 



