INTRODUCTION TO SOCIOLOGY 93
extend certain others. Although the geographical structure changes incessantly, it can be considered as one of the relatively constant factors of the structure, and consequently of the limits of the distribution of societies. In all cases, the social bound- aries are always in constant relation to the geographical limits, and move, or at least are modified, in connection with the latter. If we take a glance at the present geographical structure of our globe, we note that the solid portions are divided into three large masses, separated by the oceans. Europe, Asia, and Africa form the oriental mass of the globe; the two Americas, the occidental mass. Australia, the smallest of the continents, forms the southeastern portion of the ancient world. Around these three continental masses emerge islands, generally united in groups or archipelagos. These are usually lands torn away from the continents. Certain ones have been produced by upheavals.
The total continental land area is about 4,000,000 square kilometers; that of the islands, 200,000 square kilometers. Asia is larger than Europe, Africa, and Australia together. The area occupied by water is much larger; it is :: 2.8: 1.
If one passes a meridian through the island of Ter, the orien- tal hemisphere, from the point of view of land, is to the occi- dental :: 25^:1; likewise the northern hemisphere is to the southern, the two being separated by the equator, :: 3: I.
Thus our globe is divided into two hemispheres, chiefly water, but one of which is more continental than the other. Geog- raphers divide the globe into two hemispheres, still more dis- tinct, the one being terrestrial, but where the water is still to the land :: 1.22: I, the other being aquatic, where the water is to the land :: 11.3:2. This classification is at least as natural as the preceding, and aids in the interpretation of the evolution of societies according to their situation in one or other of these conditions.
In all these cases the earliest origins and the most general present conditions are aquatic. Certain terrestrial mammals, as the whale, have returned to their liquid element. Other animals are amphibious ; man has carried everywhere, in himself, his
