250 THE WORLD OF LIFE chap. 



area in South America in which these Tertiary marsupials have | 

 been found, taken in connection with the enormous areas of 

 geologically unexplored land in Asia and Australia, should make us 

 very cautious in assuming such vast and physically improbable 

 changes of land and sea at such a comparatively recent epoch. 

 The theory of land-connection also introduces enormous difficulties 

 of various kinds which it is well briefly to consider. If we suppose 

 an absolute land-connection in order to allow the marsupial type to 

 have entered Australia from temperate South America, we have 

 to face the incredible fact, that of the whole varied mammalian 

 fauna of the latter country this one group only was transmitted. In 

 these same deposits there are found ancestral hoofed animals of 4 

 small size (Pyrotherium) ; numerous rodents allied to cavies and:| 

 porcupines ; a host of Edentata allied to sloths, ant-eaters, and 

 armadillos. These, taken altogether, are many times more 

 numerous than the marsupials ; they were more varied in structure 

 and mode of life; and it is almost incredible that not one; 

 representative of these somewhat higher forms should have reached, 

 the new country, or having reached it should have all died out,' 

 while the inferior group alone survived. Then, again, we know that J 

 birds and insects must have abounded in South America at the; 

 same period, while the whole 7000 miles of connecting land must 

 have been well clothed with vegetation to support the varied life, 

 that must have existed upon it during the period of immigration. 

 Yet no indication of a direct transference or interchange of these 

 numerous forms of life in any adequate amount is found in either. 

 Australia or South Temperate America. We can hardly suppose 

 such an enormous extent of land to have been raised above thei 

 ocean ; that it should have become sufficiently stocked with life tc| 

 serve as a bridge (7000 miles long!), and that a few very smal: 

 marsupials only should have crossed it ; that it then sank asj 

 rapidly as it had been formed ; with the one result of stocking 

 Australia with marsupials, while its other forms of life — plants, birds j; 

 insects, molluscs — show an unmistakable derivation from the If 

 Asiatic continent and islands. A careful examination of a large! 

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

 proportionate height of land and depth of ocean at p. 345 of m; ; 

 Darwinism, together with the argument founded upon it, will 

 I think, convince my readers that difficulties in geographical! 

 distribution cannot be satisfactorily explained by such wildly 

 improbable hypotheses. If the facts are carefully examined, it wilj 

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

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

 create more serious difficulties than those which they are suppose^ 

 to explain. People never seem to consider what such an explans 

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



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