THE PALEOGEOGRAPHICM. RELATIONS OF ANTARCTICA.^ 



By Charles Hedley, F.L.S., 

 Assistant Curator of the Australian Museum, Sydney, New South Wales. 



1. INTRODUCTION. 



Testimony in support of alteration in temperature and contour of 

 Tertiaiy Antarctica is almost wholly based on a comparison of the 

 living fauna and flora of surrounding countries. While biologists 

 in general, led by Wallace, Sclater, and Hutton, opposed the idea 

 of an extended and habitable Antarctica, geographers hesitated to 

 adopt an hypothesis the arguments for which lay in a foreign field. 

 But of late years most of those engaged in its discussion have been 

 supporters of extension, so that the theory has advanced from the 

 position of a disparaged heresy to that of an estabhshed view. 



Accustomed to rely on biological evidence in the form of paleon- 

 tology for important and far-reaching generaHzations, geology 

 may now accept from biology this theory of former Antarctic exten- 

 sion. Thereby is acquired a correlation of chmate, of time, and of 

 continental change, while incidentally a new light is thrown on the 

 question of the permanence of ocean basins. 



It seemed nothing unusual to find a similar fauna and flora, even 

 to the extent of a large proportion of identical species, on the sub- 

 antarctic islands aU around the world. But collectors working in 

 South Temperate and even in South Tropical Zones were surprised to 

 find related species and genera in opposite hemispheres. This corre- 

 spondence is more pronounced in primitive groups and grows clearer 

 southward. 



First, it was realized when the famous botanist, Sir J. D. Hooker, 

 pointed to the distribution of the southern pines as indicating a 

 common origin. (Hooker, London Journal of Botany, vol. 4, 1845, 

 p. 137.) 



The relations of a southern fauna linking Australasia to South 

 America were sketched firm and clear by a master hand in Prof. 

 Huxley's essay on the classification and distribution of tlio gallina- 

 ceous birds. (Huxley, Proc. Zool. Soc. 1868, p. 294.) 



' Reprinted by permission from the Proceedings of the Lirmean Society of London, session 124, 1911-12. 

 Read June 0, 1912. 



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