90 Hypothetical Continents. 



and the plants of American eocene deposits and of European 

 (notably Swiss) miocene ; between the shells of the Faluns and 

 those which are now found in eastern seas ; between the 

 eocene mammals of Europe and the existing tapirs of South 

 America; and, finally, between the eocene plants of Europe 

 and the existing flora of Australia. Many other examples 

 might be given, but we have selected these as specially bearing 

 on the subject of this article. There are also instances of 

 " isolated faunas/' such as those of Australia and Madagascar, 

 which present some very curious differences from the animal 

 population of the nearest continents. 



Now " hypothetical continents/ - ' the term I have chosen as 

 the title of this article, have been invoked to account for both 

 classes of phenomena, and in the following pages I shall 

 endeavour to investigate the probability of their furnishing 

 the true explanation of the facts in each case. 



Of these " hypothetical continents/'' the most celebrated is 

 the Atlantis, partly on account of its having been the first 

 proposed to explain a natural history difficulty, and partly on 

 account of its name and position giving it an appearance of 

 truth, by resolving an ancient legend into a scientific fact. This 

 great continent, or " sunken island/'' was used by Professor 

 Unger to account for the similarity of the miocene flora' of 

 Europe to the recent flora of America; it has formed the 

 subject of several essays by distinguished botanists and geolo- 

 gists, and has been popularly illustrated on more than one 

 occasion ;* its prominent features are therefore tolerably well- 

 known. 



A less known theory of Professor linger' s is that of a com- 

 plete land-connection between Europe and Australia during* 

 the eocene period, an idea suggested by the affinity of the 

 majority of European eocene plants to those now living in 

 Australia, the remainder belonging to genera now exclusively 

 Asiatic, t 



A third theory is Dr. Sclater's hypothetical continent, " Le- 

 muria," stretching from Hindostan through Madagascar to the 

 West Indies. J Dr. Sclater believes that this continent must 

 have existed on account of the affinity of some of the curious 

 mammals of Madagascar to some now living in India, and to 

 others existing in the West Indies ; and on account of tho 

 entire distinctness of the Madagascarian from the South- African 

 mammalian fauna. 



Now these theories depend upon the principle that the 



* See especially Journal of Botany, No. 25, January, 1865, p. 12 ; LyelPs 

 Elements, sixth tdition, p. 2G5 ; and Natural History lleview, 1862, p. 119. 

 t Neu Holland in Europa, and Journal of Botany, No. 26, February, 1865. 

 X Quarterly Journal of Science, vol. i. No. 2, p. 213, 1864. 



