30 WAGES AND EMPIRE 



of their requirements ; such as the wheat bred to 

 ripen earher than the common varieties. The invention 

 of this plant has made cultivable land in Canada and 

 Siberia, which owing to the early frosts was before re- 

 garded as useless, and every further improvement in 

 the breed enlarges the cultivable area of such land. 



Another of the means which has made it possible 

 to cultivate much land that before was useless arises 

 from the increase in the yielding capacity of plants. It 

 thereupon becomes profitable to cultivate land which 

 with smaller yielding plants would not pay. 



Moreover, the general abolition of fallows alone 

 produced an effect equal to doubling the land of the 

 world. Formerly each piece of land was exhausted 

 by the bearing of a single crop, and must be allowed to 

 lie idle for a year or more to recover naturally its fer- 

 tility. The inexpensive fertilisers of the present day 

 however render the land permanently cropable. 



