In comparing the continents, we at once notice certain resemblances. The
first is the tapering to the south, which is seen in Greenland, North
and South America, Africa, and Australia (Tasmania). Another is the
southward-running peninsulas which characterize Europe and Asia. We may
notice, too, that the general lines of the Old World, broad in the
north, tapering in the south, resemble those of the New World,
especially if we include Australia (Tasmania), and compare its position
with that of South America. There is also a certain uniformity in the
distribution of relief. Notice the so-called Mid-World and Pacific
Mountain systems, which may be traced in the mountains of Central
Europe, North Africa, Central Asia, the islands of the Pacific from
Japan to New Guinea, and the lofty mountains of North, Central, and
South America.
[Illustration: =DIAGRAM SHOWING AVERAGE HEIGHT OF THE CONTINENTS=]