iv BEGINNINGS OF AGEICULTUEE 43 



only water that was necessary to make their land 

 fertile, the idea of bringing water, that is of 

 irrigation, would occur to them. 



Another point which must have been of great 

 importance is that cultivated plants mostly arose 

 north of the Equator, and botanists have shown 

 that annual plants, that is, those which only live 

 one year, are more common in the north than in 

 the far south. A great many cultivated plants are 

 annuals, which grow much faster than perennial or 

 long-lived herbs or trees, and the idea of cultivating 

 annuals would naturally arise early. Wheat, barley, 

 oats, millet, rice, maize these are only a few of the 

 important annuals, and all these come from the 

 more northern part of the earth's surface. 



We might say also that it was because the 

 useful plants grew naturally in the countries where 

 agriculture began that they were cultivated, only 

 we are not quite sure how far this is true. What 

 is true is that the cultivated plants were developed 

 from plants growing in the regions where agriculture 

 started, but it is difficult to be sure that it was 

 only in these countries that plants grew which 

 were worth cultivating. For instance, practically 

 no useful cultivated plant comes from Australia, 

 but till the white man went, nobody thought of 

 trying to cultivate plants there. We might say 

 that when the white man went he should have 



