THE BIRDS' COMPASS 



gested, that these birds simply followed the coast 

 line until they reached their island home. 

 Though why they should go south instead of 

 north, or turn westward through the Florida 

 Keys instead of eastward to the Bahamas, where 

 many Terns of their kind live, is not explained. 



However, to make it perfectly clear that the 

 birds were not guided by landmarks of any kind, 

 Professor Watson finally sent several Sooty and 

 Noddy Terns across the Gulf of Mexico to 

 Galveston. This city is distant eight hundred 

 and fifty-five miles from the Tortugas, and the 

 intervening water is unmarked by islet, shoal, or 

 reef. Nevertheless, one of the birds returned to 

 Bird Key in six, one in seven, and a third in 

 twelve days from the time of release. 



It is, therefore, practically certain that the 

 birds used could not have been familiar with 

 the route, nor could there have been other birds 

 of their kind to guide them. From the hold of 

 the vessel they certainly could not have observed 

 the water over which they were sailing, and if 

 they had, it would not have given them a clew to 

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