ON THE DISTRIBUTION OF PLANTS. 197 
mould. necessary for heather and wood is _ yet formed; on 
sunny screes, if the thieketa are not too dense; on woodless sandy 
- downs, in the crevices of rocks; on open bogs, jong in lakes not too 
in spec The screes and the limestone rocks of the coast and the 
slates of the coast mountains are much poorer in ogg s than those 
of the inner fjords and eastern parts. It is e otherwise with 
plants which are not green, and which are not fond of light. 
hymenomycetous fungi, for imstance, are fond of shade, and we find 
yah of them 1 in woods. The coniferous woods have species peculiar 
inane grow in woods of both descriptions. Many fungi are only 
found under the shade of beech sa I have found many of them 
in our two principal beech woods by Laurvig and north of Bergen. 
Tne woodless high mountains, on the contrary, appear to be poor 
in fungi, as far as our researches have yet gone. These plants are 
fond of shade and vegetable mould, and the mountains are poor in 
either. 
There is a remarkable phenomenon concerning the distribution 
of species which must now be mentio ned. In the distribution of 
many species, nay, even in that of whole groups, there are gaps, 
shown by Sir J. D. Hooker, commonly many ‘ endemic 
169 are found also in other parts. But even the species 
poelias to the islands - more or less eine to Fthdes of the 
continents, and we must thus conc clude that the plants of = 
i i immigrated 
to far-off places than the 
Oc: iayine ourselves for rth ‘present only with the wild flora, we 
do not speak of the influence of man, by which, voluntarily or 
involuntarily, plants migrate over large areas. Putting this influence 
of aside, we may, from the very nature of the flora of these 
~ only a dozen pheenogamous species possibly introduced on 
