INTRODUCTORY CHAPTER. lxxiii 



itself in union with Arabia. That some such connection has existed it is 

 impossible to doubt, and by it the vegetation of the Orient gained extension 

 into Socotra. 



But there are those other Asian forms which do not occur anywhere in 

 south-west Asia to account for — Indian and other Eastern affinities. How 

 did they reach Socotra 1 An elevation of land that would unite Socotra and 

 Madagascar with Africa — an elevation which certainly took place — would, if 

 increased and continued over a wider area, produce some interesting changes 

 in surface features. Not only would the Gulf of Aden disappear by the union of 

 Africa with Arabia, but there would be no Persian Gulf, and the Euphrates 

 would pour its waters through a delta extending over a large part of the Arabian 

 Sea, and through this delta the Indus would also discharge, the coast-line of 

 the Indian Peninsula being advanced to some extent. South of the equator 

 Madagascar would join the Seychelles, which in turn, through the Malha and 

 Nazareth banks, would run into the larger Mascarene Islands. In this way, 

 then, Africa would have an irregular coast-line prolonged greatly south of the 

 equator into the Indian Ocean, and running up with an advance upon its 

 present line until it reached its north-eastern limit outside and south of Socotra. 

 Thence an advanced land-surface of Asia would extend across the Arabian Sea 

 into the Indian Peninsula. It appears to me that we must assume that some 

 such land-surface as this existed to aid us in explaining the migration westward 

 to Socotra of Indo-Malayan types, several of which have a striking extension 

 into Madagascar and the Mascarene Islands. Lieutenant-Colonel Godwin- 

 Austen asserts that the relationship of the Socotran land-shells are such as to 

 warrant the conclusion of a prolongation of land-surface which would stretch from 

 Madagascar to Ceylon across the Indian Ocean. Professor Von Martens ques- 

 tions this conclusion, and the evidence upon which it rests, and Dr Schweinfurth 

 is also inclined to doubt a near connection with Madagascar. Mr Blandford, too, 

 doubts the nativity of a lizard in Madagascar, because it is now found in Socotra, 

 from which I gather that he would not allow a land-connection between Socotra 

 and Madagascar. But the evidence from the plants leaves no room for ques- 

 tioning the determinations and spontaneity of forms, and the Madagascar and 

 Mascarene affinities are thoroughly assured, as are those with India and the 

 East. I do not think it is requisite to suppose so large a land-surface to have 

 existed as Lieutenant-Colonel Godwin-Austen assumes,* but a greater exten- 

 sion of land, and on the lines above sketched, appears to me to be required by 

 the facts. I imagine that these Indian and Madagascar and Mascarene types 

 were enabled to reach the land-surface, now Socotra, about the period when 

 the old African flora existed, and they help one to the conclusion that a separa- 

 tion from Africa and Asia took place when that old flora was general in Africa, 

 and then they, with the remnants of that flora, formed a conspicuous part of 



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