THE MYSTER Y OF MIGRA TION 1 99 



The first task undertaken was to note and 

 separate these lines of flight, and to determine 

 whence and whither the birds were going. We 

 now know whence the birds come to us for 

 the summer, and the roads by which they come. 

 Africa sends perhaps the greatest number. Some of 

 these start for England from Algiers and the Medi- 

 terranean coast. Others have wintered in the Nile 

 Valley, and descending to its mouth for the Sahara 

 desert is almost as dreaded by the birds as the 

 Atlantic Ocean skirt the shore towards the Straits 

 of Gibraltar. Some fly across to the Balearic Islands, 

 and thence through Catalonia, and down the Garonne 

 Valley to the Biscayan Coast. Others pass by 

 Sardinia and Corsica to the valley of the Rhone. 

 But the main body cross at the Straits of Gibraltar, 

 follow the east coast of Spain, pass up the valley of 

 the Ebro, cross the Pyrenees near Pampeluna, and 

 then follow the Bay of Biscay till they reach Cape 

 Finisterre, and fly across the channel to the Lizard 

 or the Start. France contains the three other main 

 roads of the spring migrants. The most southerly 

 stream passes up the Rhone Valley to Lyons, crosses 

 to the Loire Valley at Orleans, and passes thence 

 via Cape La Hogue to the Start Point. The stream 

 from Turkey and Greece passes up the Italian coast, 

 through the Swiss passes, into central France, down 



