GEOGRAPHICAL DISTRIBUTION OF TREES. 47 
The mountain ash, Sorbus aucuparia, L., Pyrus aucu- 
paria, Gaerton, is very frequently met with everywhere in 
Norway, and in an ordinary summer its fruit comes to 
maturity. On mountains it extends to the limits of the 
birch, where it stops. With its branches of red berries, 
which offer a food greatly sought after by birds in great 
numbers, it gives to the mountain slopes in winter a 
peculiar and animated appearance. 
In supplying such details we are drifting away from the 
eonsideration of what are generally know as forest trees to 
what are generally known as wild fruits; and why not? 
With these may be mentioned several others. 
The crab apple, Pyrus malus, L., is met with here and 
there in a wild state up to the island of Yteros, on the 
Drontheim fiord, 63° 49' N.; in the south it does not 
extend above 500 metres of altitude. 
The gean, or wild cherry, Prunus avium, is met with in 
the interior of the Sogne fiord, at Urnes, where there is a 
small wood of it, 12 metres, or 40 feet high, and 30 centi- 
metres, or 20 inches in diameter. 
The bird-cherry, Prunus padus, L., is generally diffused 
throughout the whole of Norway, even to the Tanaelv ; in 
East Finmark, 70° 20' N., its fruit ripens. In South 
Norway it attains the altitude attained by the pine, and 
sometimes it extends to a higher elevation. 
The blackthorn, or sloe, Prunus spinosa, L., is found in 
South Norway, up to 60° N. 
The barberry, Berberis vulgaris, L., shows itself in a 
sub-spontaneous state in many places up to 64° N. , 
The gooseberry, Ribes grossularia, L., is found here aud 
there in a sub-spontaneous state in low-lying countries up 
to 63° N, 
The red currant, Ribes rubrum, L., is found pretty 
generally spread over the whole of the country up to the 
eastern frontier of Finmark; and on mountains it grows 
beyond the limits of the pine. 
The juniper, Juniperus communus, L., generally presents 
