64 THE ENTOBIOLOGIST. 



many places has altered little in form since the ice left it. The 

 surface of the rock is heing slowly i)roken up l)y ve<);etation — by 

 Scotch fir principally, that species with spruce and juniper being 

 the only conifers. 



The spruce tbrives on the rocky talus on the valley sides, but 

 the Scotch fir grows on the rocks,, and seedlings may be seen 

 rooted in the smallest cracks in wbat appears to be solid rock. 

 In the forest tbe toj^s of the hills are often smooth, rounded 

 masses of rock covered only by patches of moss — rounded pads 

 which are not attached to the rock, as one may find to one's cost 

 if one sets foot on one carelessly on a tlope. On lifting the 

 moss it will be seen that the rock is being disintegrated beneath 

 it, there being numbers of loose detached fragments. As these 

 patches of moss are easily moved and must be frequently dis- 

 placed by snow or by other effects of climate, tlie disintegration 

 is distributed over the surface and tends to maintain the smooth, 

 rounded outline. Scotch fir and spruce will occasionally 

 germinate in the pads of mo?s. I often pass a Scotch fir which 

 is growing on the top of a solid detached block of stone. It has 

 started as a seedling on the top, bul the root has travelled 4 or 

 5 ft. down the back of the block and has rooted in the ground 

 below. Scotch fir will root in the smallest crack, and when it 

 splits the rock the root may be seen to have spread laterally, 

 forming a soliil wedge 3 or 4 in. wide. In geological manuals 

 not enough credit is given to vegetation for the work it does in 

 breaking up rocks. I feel sure tiiat more work is being done in 

 south Norvvay by vegetation than by frost. The deep covering 

 of snow that remains often till late in the spring protects the 

 rock from the effects of frost. To break up solid domes of 

 crystalline rock is not an easy matter, and I do not think water 

 and frobt would have much effect without the help of vegetation. 



Deciduous trees are founii throughout the forest, but they 

 are mostly cut for firewood, and are rarely allowed to reach an 

 age suitai)le for timber. Birch and aspen are most abundant, 

 with oak, ash, lime, elm, Norway maple, alder {Alnus glutinosa 

 and A. incana), with Bhavmns frangvla and hazel. Wild rasp- 

 berries are abundant in clearings with patches of golden rod and 

 spiraea. 



In the forest, which is generally very open, consisting of 

 trees of all ages, the cutting being mostly by selection, there is 

 a thick undergrowth of Vaccinium viyrtillus, V. alipinosiwi and 

 V. vitis idoea, often overrun with Linncea borealis, which naakes 

 tbe air fragrant with its scent. On the higher ground Empetruin 

 n'lgnun. and Arctostaphylos mm-ursi abound, trailing in matted 

 masses over the rocks. Among the commoner plants of the 

 forest are Anemone iiepatica, Cornus snecica, TiientaliA eiiropea, 

 Smilicina bifolia, Polijgala vulgaris, Melampyru>ii pratense, Meny- 

 anthes trifoliata. Pyrola media and P. rotundifolia are common, 



