woods and pastures, need less labour, where we know from experience that women are more fertile than in the plains, and where a great expanse of slope affords only a small level tract that can be counted on for vegetation. On the other hand, contraction is possible on the coast, even in lands of rocks and nearly barren sands, because there fishing makes up to a great extent for the lack of land-produce, because the inhabitants have to congregate together more in order to repel pirates, and further because it is easier to unburden the country of its superfluous inhabitants by means of colonies.