rOPULATIOX, 



453 



surprisingly from province to province, according to race, climate, and social 

 conditions. In the south marriages are most frequent, while the hirth rate is 

 highest in the Kama and Lower Volga basins, and. the mortality greatest in the 

 governments of Olonetz and Moscow. In general there is a normal increase in all 



Fig. 239. — Density of the Population in East Euuope. 



E.ifG. 



Under 3. 



Inhnhitants to a Square Mile. 



3 to 26. 



26 to 55. 



55 to 110. 



Over 1G3. 



the provinces, though local migration in times of distress has occasionally caused a 

 falling off in such poor districts as Vitebsk, and in governments such as those of 

 Moscow, Kaluga, Tula, Riazan, which have already become centres of the industrial 

 proletariate classes. The increase is always rapid in Poland, on the Euxine, and 

 along the Volga between Kazan and Saratov. 



