Chapter XIV: Plains, Steppes and Deserts

Relief of the sea floor--Mean elevations of the continents--Distribution of relief--Homologous reliefs and homologous histories--Anthropo-geography of lowlands--Extensive plains unfavorable to early development--Conditions for fusion in plains--Retardation due to monotonous environment--Influence of slight geographic features in plains--Plains and political expansion--Arid plains--Nomadism--Pastoral life--Pastoral nomads of Arctic plains--Historical importance of steppe nomads--Mobility of pastoral nomads--Seasonal migrations--Marauding expeditions--Forms of defense against nomad depredations--Pastoral life as a training for soldiers--Capacity for political organization and consolidation--Centralization versus decentralization in nomadism--Spirit of independence among nomads--Resistance to conquest--Curtailment of nomadism--Supplementary agriculture of pastoral nomadism--Irrigation and horticulture--Scant diet of nomads--Effects of a diminishing water supply--Checks to population--Trade of nomads--Pastoral nomads as middlemen--Desert markets--Nomad industries--Arid lands as areas of arrested development--Mental and moral qualities of nomads--Religion of pastoral nomads.

CHAPTER XV. MOUNTAIN BARRIERS AND THEIR PASSES

Man as part of the mobile envelope of the earth--Inaccessibility of mountains--Mountains as transit regions--Transition forms of relief between highlands and lowlands--Piedmont belts as boundary zones--Density of population in piedmont belts--Piedmont towns and cities--Piedmonts as colonial or backwoods frontiers--Mountain carriers--Power of mountain barriers to block or deflect historical movement--Significance of mountain valleys--Longitudinal valleys--Passes in mountain barriers--Breadth of mountain barriers--Dominant transmontane routes--Height and form of mountain barriers--Contrasted accessibility of opposite slopes--Political and ethnic effects--Persistence of barrier nature--Importance of mountain passes--Geographic conditions affecting the historical importance of passes--Passes determine the transmontane routes--Navigable river approaches to passes--Types of settlement in the valley approaches--Pass cities and their markets--Pass peoples--Their political importance.