GEOGRAPHICAL DISTRIBUTION OF TREES. B 
Tn the same zone may be observed the growth of the alder, 
Alnus incana, D, ©., known in England as the hoary-leaved 
alder. It is met with very frequently so far north as West 
Finmark, where it may be seen with a height of 20 metres, 
66 feet 8 inches, and a diameter of 30 centimetres at the 
level of the ground; and it grows to almost the same alti- 
tude as the beech. 
The Alnus glutinosa, Gent., the common alder of Britain, 
is much less frequently met with. It flourishes always in 
low valleys along the banks of streams and a humid soil. 
It is scarcely to be met with above an altitude of from 250 
to 300 metres; and its Polar limit is 64° N. lat. 
Of the oak, two species are found growing wild in Nor- 
way, the sessile fruited oak, Quercus robur, W., and the 
common oak, Q. pedunculata, W. The latter is found on 
the west coast up to 63° N.; but the planted oak, up to 
66° N. In the southern parts of the country it scarcely 
ever extends beyond 300 metres above the level of the sea. 
There are small forests of the common oak on the coast 
between Arendal and Flekkefiord, on the shore of the 
diocese of Bergen, and in Romsdal. 
The beech, Fagus sylvatica, L., when planted, flourishes 
up to Stegen in Nordland, 67° 56’ N.; and at Drontheim, 
63° 26’ N., its seeds come to maturity. Asa wild tree, it 
is not met with beyond 61° N. Even in the southern 
parts of the country it does not extend beyond 250 metres 
above the level of the sea. It forms small forests near 
Tonsberg, near Larvik, near Arendal, and a little north of 
Bergen, at Swim, an annex of Hardanger, 66°35’ N. At 
this point is found the most northern forest of wild beeches 
in the world. 
The elm, Ulmus montana, S., the wych elm of Britain, is 
met with up to the 67° of north latitude. Its limit of 
elevation is generally from 500 to 600 metres above the 
level of the sea. At Solvorn, near one of the branches in 
