CHAP, XIX 



THE MADAGASCAR GROUP 



425 



sea — much deeper than that which divides Madagascar 

 from Africa, and we have therefore no reason to imagine 

 tl: eir former union. But they would nevertheless greatly 

 facilitate the introduction of Indian birds into the Mas- 

 carene Islands and Madagascar ; and these facilities existing, 

 such an immigration would be sure to take place, just as 

 surely as American birds have entered the Galapagos and 

 Juan Fernandez, as European birds now reach the Azores, 



gO| 30| 40| 50l 60| 70! 80| 



MAP OF THE INDIAN OCEAN. 



Sliowiug the position of banks less than 1,000 fathoms deep between Africa and the 

 Indian Peninsula. 



and as Australian birds reach such a distant island as New 

 Zealand. This would take place the more certainly because 

 the Indian Ocean is a region of violent periodical storms 

 at the changes of the monsoons, and we have seen in the 

 case of the Azores and Bermuda how important a factor 

 this is in determining the transport of birds across the 

 ocean. 



