2, ate Y, Us) 9 «peel oe. se ie Soe Fee ie 3S ~~) whan &, ‘A o@w i? *S 
a NR ao ei ME SE tO ERIE TS he BSS Geta t tee NE al SM At LA a cr 
A ee ‘a i Way hh 8 ates | 
CRT abs 9s ¥ 
‘ A ¢. 4 438 7S tructural one Ph -tysiological bac 
it r ine . <9 rd pied a “ 
ay = . - ; ¥~ 4 z PK het? A 
if i b Pe e- i ‘> ~% ee > Ay ‘ ‘e 
- 
a 
on he candy products of the icon fo masses gt 
granitic rock, and form the ‘dry Tundren.’ These latter % . 
furnish food for animals, and are therefore more valuable | 
than the former. | ee e 
2. The Europao-Siberian Forest-Region. — es. 
The general climatic character of this region, which gives _ 
rise to the uniform nature of its vegetation, is the uniform 
average temperature of its entire vegetative period, and the 
absence of a rainless season to interfere with the growth of 4 tae 
its trees. Combined with these is a condition pecuhanl a ie 
favourable to its arboreal vegetation, a period of activity 
also because they retain in the soil and in their tissue larg 
always amounting to more than three months in each year, . a ‘ 
which distinguishes it from the Arctic Region ; while the 
permanent moisture of the ground from constant rainfall, 
separates it from the steppes which lie to the south and from BS 
the Mediterranean district. : . 
On the borders of the ocean, especially on she Adame 
coasts, the sea produces an effect on the climate, moderating ~ 
both the cold of winter and the heat of summer, and thus 
producing a mild maritime climate, in contrast with themore 
widely extended continental climate. The longer duration 
of the period of vegetation, and the gradually increasing — 
temperature of the summer, are noticeable in passing | . ; 
through this region from north to south. ey) 
There are also large tracts of country in Bee the 
forests have been made to yield to cultivation, and whieh a 4 
render the general term for the region somewhat inapplicable. ~ = 
This clearing of the forests in Europe has also made the a 
climate more continental by diminishing the rainfall, ’ 
This destruction of forests alters the climate, not only because — 
the trees shade the ground and hence keep it cooler, bu 
quantities of moisture, which are gradually restored to che 
atmosphere by transpiration. : 
