434 



SCIENCE 



[N. S. Vol. XXXII. No. 822 



continental seas, between the Australian-New 

 Zealand region and Antarctica (Wilkes Land 

 and South Victoria Land, the two doubtless 

 continuous) on the one hand, and South 

 America and Antarctica (Graham Land) on 

 the other. We are quite justified in believing 

 that these epicontinental sea-bottoms were land 

 areas for long periods of time and have since 

 subsided beneath the ocean level. 



Here then was the land connection which 

 furnished not only the highway for the inter- 

 change of forms of life between the southern 

 continents, but also a vast territory of sub- 

 permanent residence and consequent multiple 

 development of those forms during the inter- 

 vals that elapsed between their successive 

 wanderings. So far as area goes, it was prac- 

 tically as though the continent of Africa were 

 to be laid down on the south polar region to- 

 day, with its center on the pole. But it would 

 be an Africa well watered throughout, even 

 somewhat increased in size, perhaps not much 

 changed in contour, with very different faunal 

 and floral elements. 



Alexander Land is probably a continuation 

 of Graham Land, and King Edward VII Land 

 is an extensive reach that probably connects 

 these with South Victoria Land. On the op- 

 posite side, Coats Land and Enderby Land 

 probably meet and form a land reach directly 

 south of Africa, probably also continuing to 

 Graham Land on the one side and to Wilkes 

 Land on the other. Thus we almost certainly 

 have to-day in Antarctica one vast compact 

 land mass forming a continent more than 

 twice the size of Australia, or even larger 

 than South America and almost the counter- 

 part of the latter in outline. There is no such 

 continental mass in the north polar region. 



In former ages the elevation of Antarctica 

 above sea level was, as a matter of course, 

 much less than now. Shackleton has found to 

 exist there at present an immense plateau-con- 

 tinent with twice the average altitude of Asia 

 — the highest of the other continents. The 

 upheaval of Antarctica has certainly been go- 

 ing on for ages. During Tertiary times the 

 continent was probably not dissimilar in aver- 

 age elevation to present-day South America 

 and Asia, and its subsequent further uplift- 



ing during periods of diastrophic activity has 

 been the immediate cause of its present iso- 

 lation through the subsidence of its sheK- 

 lines. Probably the Australian- Antarctic- 

 South American land-connection was main- 

 tained from early Paleozoic time to some- 

 where about the Jurassic period. This is in- 

 dicated by the present distribution of the mus- 

 coid flies in Australia and South America. 

 The writer would like to know whether this 

 view is borne out by a study of other elements 

 of the two faunae. At all events, it appears 

 that South America was the first to lose its 

 connection wih the southern continental mass. 



Africa was also quite certainly connected 

 with Antarctica, and through it with South 

 America and Australia, its connection with 

 the main mass having apparently persisted to 

 a much later date than that of South America, 

 if we may credit the evidence of present mus- 

 coid fly distribution in the continents con- 

 corned. Comparatively shallow depths must 

 exist somewhere between the African region 

 and Antarctica. The southern extremity of 

 Africa is in latitude 35° south, and its connec- 

 tion with the southern continental mass im- 

 plies a land stretch of some 5,000 geographic 

 miles in opposite directions to Australia and 

 South America respectively, along the edges 

 of the south polar region. It is likely that 

 the African connection was maintained by a 

 comparatively narrow isthmus, and until about 

 Miocene times. 



Add to Antarctica as above restored the 

 great extents of land area represented by the 

 Paleozoic and Mesozoic continents of South 

 America, Africa and Australia, all continuous, 

 with many high mountain ridges interspersed, 

 all in the main under a mild and equable cli- 

 mate, and we have a vast range of land sur- 

 face which, in its possibilities for the evolution 

 of varied forms of life, quite staggers the 

 imagination. It is even possible to imagine 

 a land connection of Africa and South Amer- 

 ica, on the one hand, through Antarctica and 

 Australia, with, on the other hand, Malaysia 

 and the continent of Asia. There has cer- 

 tainly been connection of Malaysia with Aus- 

 tralia, and probably with the Asiatic main- 

 land whose original confines were the general 



