ON THE DISTRIBUTION OF PLANTS. 201 
If the rainfall changes in the course of time, the change must be 
ag least palpable in the driest and the wettest places. Places with 
mean degree of moisture must be most subject to change. All 
bees places mentioned above must be considered to be unchange- 
able habitats. And thus it is clear that remains from old floras can 
survive only in such places. It is not because such localities are 
more — to seeds brought distant places that we find 
the ; this is borne out by comparing them with places 
which lett lost their flora by local events, and are invaded only by 
the common plants of the neighbourhood. And it is borne out still 
mere clearly when we consider that rare mosses are most plentiful 
n hidden rock-crevices, and rare fungi in the de of forests 
iets the ground is not ‘easily accessible to spores brought from a 
distance. 
Though I do not profess to be a zoologist, I do not hesitate to 
state that even amongst the animals there are oe ps of species 
catineee! ae to the above-named groups of plants. Animals and 
plants are interdependent in many ways. ere are many insects 
peculiar to our vetiae frescos and the Dovrefjeld is as interesting 
to the entomologi o the botanist. Our west coast is said to 
yield to the ee pre wanting in the eastern — which 
t n 
limestone. Thus, I think, we may conclude that the cotlogeal 
events ve bygone times are reflected in both the flora and the fauna 
of the present da 
e first catmeenlit whe propounded this doctrine, at least as 
eaieas the plants, was Edwar d Forbes. He demonstrated that the 
Ice Age influences even the pai distribution of plants. The Ice 
Age explains how the mountains of the temperate zone came to 
possess arctic species. During glacial times arctic plants flourished 
even in the lowlands of Middle Europe. As climate grew milder, 
they retired to the mountains and rthe arctic lowlands. Dr. 
ant-remains in the re a. of Middle Europe. But jee 
this flora immigrated to our west ge from South Sweden, om 
most of its species still occur around the Christianiafjord, where we 
i Se ye conte remnants of it, especially in the subalpine regions, 
