INTESTIGATION OF TEMPERATUEE CHANGES. 237 



present writer has been called to tliis dying out of the forests, in the 

 course of repeated visits to the Alps and especially in one made since the 

 writing of this volume was begun. It seems to him hardly to be doubted 

 that the forests in higher parts of both the Swiss and the Tyrolese Alps are 

 suffering from a change of climate, and not, as is usually supposed, from the 

 attacks made \ipou them by man. These deleterious effects of climate can 

 be studied only at the extreme limits of forest growth, and at elevations 

 and in positions where the difficulty of access and the character of the timber 

 combine to allow the trees to remain in their natural condition. Similar facts 

 in reference to the movement of the northern line of forest vegetation to- 

 ward the south, in the valley of the Yenisei River, will be found in the various 

 accounts of the geography and geology of Siberia published by the Russian 

 scientific explorers of that region. In many places along the lower part oi 

 the Yenisei large trunks of trees are found imbedded in the peat morasses in 

 such a way as to show that they grew on or near the spot where they now 

 rest. From this and other similar facts, it is considered by Schmidt and 

 Middendorff that there can be no doubt that the limit of tree growth has 

 receded toward the South in later historic times.* 



According to Dr. F. v. Czerny,t it has been positively made out in Hun- 

 gary that the vegetation peculiar to the steppe is gradually working its way 

 toward the West. This, however, might be the result of a diminution of 

 moisture, and does not necessarily imply a lowering of the temperature, 

 except in the case of those who, like the present writer, consider the two 

 phenomena as causally connected. 



The fact that the name of the month of November in the Russian, 

 Polish, and Bohemian languages (and perhaps in some other Sclavonic 

 tongues) is the same as the word signifying " fall of the leaf," is looked 

 upon by some writers as indicative of a change of climate in the region 

 where those languages are spoken. The trees in that part of Europe do 

 now unquestionably finish shedding their leaves before November begins, 



* See F. Schmidt, Wissenschaftliche Resiiltate der zur Aufsuchung eines angekiindigten MamniuthcadaTers 

 von der kaiserlichen Akademie der Wissenschaften an den unteren Jenissei ausgesandten Expedition, in Mem. St. 

 Petersburg Academy, Vol. XVIII. 1872, No. 1, p. 26. 



t In "Die Veranderlichkeit des Klimas und ihre ITrsachen," Wien, 1881. Dr. Czemy mentions the follow- 

 ing as authorities from whom he has derived his information in regard to changes of climate in historic times : 

 Studer, Lehrtuch der physikalischen Geographie und Geologic, Bern, Chur, und Leipzig, 1847, II. Theil, pp. 

 305-308; El. Reclus, La Terre, 3d edition, II. pp. 493-497; and Miiller's Kosmische Physik, 4th edition, 

 pp. 510-513. 



