THE LARCH IN GERMAN FORESTS. 49 



as we mount to higher elevations, the atmosphere becomes more 

 cloudy and dull, damper and colder), that the larch becomes more 

 sickly, and more victimised by its enemies, in the front rank of 

 which stands the Feziza. It is on the lower ground of the 

 northern Alps that we reach the natural home of the larch ; and 

 in the country of the vine, the sweet chestnut, and the walnut, 

 we find larches of noble dimensions. Owing to the compara- 

 tively warm temperature, not a trace of crooked growth is here 

 to be seen. 



On the mountains, the appearance of the larch depends in some 

 measure on the exposure of the valleys, the consequent angle at 

 which the sun's rays strike the ground, and the degree of moisture 

 of the atmosphere. For example, the narrow Val Plavna, in the 

 Middle Engadine, situated in the Eldorado of the larch, is not a 

 larch locality, but is rather one for the shade-bearing silver fir. 



It is not correct to assume that great moisture prevails at high 

 elevations in Switzerland. It is well known that the Engadine 

 forms part of the driest district of the Alps ; and consequently it 

 is there that the finest larches are seen. The temperature in the 

 Middle Engadine does not differ much from that of the author's 

 part of Germany ; and if the air of the latter were as dry as it is 

 in the Engadine, fine larches would be found there also. 



As regards rainfall, the important point for the larch is not the 

 total annual fall, but the amount that falls during the growing 

 season, i.e., from the beginning of June to the end of August in 

 the Lower Engadine. At this season there are no fogs, and the 

 sky is seldom overcast ; while if a thunderstorm brings down 

 torrents of rain, the insolation is so intense, in consequence of the 

 high altitude and the clearness of the atmosphere, that a few hours 

 after a storm the roads are again dusty. Dry air and much sun- 

 shine, which encourage transpiration, are the friends of the larch, 

 but the enemies of the fungus. Moist air and a cloudy sky, on the 

 other hand, check transpiration, and impair the vital force of the 

 larch, while they stimulate that of the fungus. It is only necessary 

 to observe lajches growing in a damp, shady place, or in a cloudy 

 region inducing limited transpiration, to arrive at the conclusion 

 that it is quite useless to plant this tree in localities where the air 

 is damp, or where the soil is unable to provide water for active 

 transpiration. 



In a damp atmosphere, the maintenance of Larix europcea in a 

 dense stock results in failure. In consequence of the clear sky and 



VOL. XVIL PART I. D 



