ground beside the gigantic cedar, and have to content themselves witli a less ambi- 

 tious place, half hidden between them. They constitute the greater part of the under- 

 wood, which is frequently so dense as to make it nearly impossible for the traveller 

 to force his way, even in the subalpine regions, not far below the tree limit itself. 



I will first in few words make mention of the most common species of trees com- 

 posing the taiga proper. 



Abies sibirica forms trees up to 30 or 35 m. high, measuring over 0,5 m. in dia- 

 meter at a man's height. It is above all characteristic in constituting the moist, dark 

 taiga together with the spruce and the cedar, and, to some extent, the birch and the 

 aspen. In alpine situations it reaches nearly to the limit of tree vegetation, represented 

 by isolated low specimens, more or less stunted, here however, being superseded by 

 the spruce and the cedar. It is frequently to be found in loamy soil, and does not 

 shun rather moist and swampy places, forming here and there underwood so dense 

 as to compel travellers to cut out a way for the pack-horses by means of axes. In 



Fig. 22. Subalpine virgin coniferous forest in llie Sayanslc 

 mountains; tlie Upper SistiUem val]e3' about 

 1600 m. above sea-level. The bushy cedar-crowns 

 overtopping the level of the surrounding wood. 



moist, mossi-grown places, Abies sibirica frequently propagates by means of vegetative 

 shoots, the lower branches trailing along the ground, or branches of fallen trees taking 

 root and bending upwards at the summit. These shoots are at the beginning dorsiven- 

 tral, like the branches forming them, but gradually pass into symmetrical ones. I have 

 observed this fact in several places, for instance near Ust Algiac. 



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