LIFE OF TERTIARY PERIOD 261) 



idly as it had been formed; with the one result of slocking Aus- 

 tralia with marsupials, while its other forms of life — plants, birds, 

 insects, molluscs — show an unmistakable derivation from the 

 Asiatic continent and islands. A careful examination ol' a large 

 globe or South Polar map, with a consideration of the diagram of 

 the proportionate height of land and depth of ocean at p. .315 of 

 my Darwinism, together with the argument founded upon it, will, 

 I think, convince my readers that difficulties in geographical dis- 

 tribution cannot be satisfactorily explained by such wildly im- 

 probable hypotheses. If the facts are carefully examined, it will 

 be found, as I have shown for the supposed " Atlantis " and 

 " Lemuria," that such hypothetical changes of sea and land always 

 create more serious difficulties than those which they are supposed 

 to explain. People never seem to consider what such an explana- 

 tion really means. They never follow out in imagination, step by 

 step, the formation of any such enormous connecting lands between 

 existing continents in accordance with what we know of the rate 

 of elevation and depression of land, and the corresponding organic 

 changes that must ensue. They seem to forget that such a vast 

 and complete change of position of sea and land is not really known 

 ever to have occurred. 



Let us consider for a moment what the supposed land-connection 

 between South America and Australia really implies. The distance 

 is more than half as much again as the whole length of the South 

 American continent, and 1000 miles farther than from Southamj)- 

 ton to the Cape. This alone should surely give us pause. P)ut 

 unless we go as far south as the Antarctic circle, the depth of the 

 intervening ocean is about two miles; and until we get near Xew 

 Zealand there is not a single intervening island. There are here 

 none of the indications we expect to find of any geologically recent 

 depression of land on a vast scale. Of course we may suppose the 

 connection to have been along a great circle within ten degrees of 

 the South Pole, but that will not greatly shorten the distance, 

 while we have not a particle of evidence for such a vast ehange of 

 climate in Mid-Tertiary times as w(nild be required to render such 

 a route possible. But the mere physical dilhculties are equally 

 great. All land elevation or depression of which we have geo- 

 logical evidence has been exceedingly gradual, very limited in 

 extent, and always balanced by adjacent opposite movements. Such 



