146 WITH THE U. S. NATURALISTS 



no matter from what point he starts, the Golden 

 Plover is able to allow for drift, for all the varia- 

 tions of the aerial currents and he strikes Hawaii 

 on the same day everj^ year as regularly as though 

 there were a track laid in the sky by which he might 

 travel. Fog, alone, confuses the birds, showing 

 that natural powers play some part in this great 

 instinctive flight. If you ask me how, if you in- 

 quire as to the compass in the bird's head, there is 

 nothing to say. Science is no Philosopher's Stone, 

 she cannot turn to the gold of easy understanding 

 all the puzzles which lie before her. Such secrets 

 yield themselves up onlj^ to long and patient labor. 

 'The stork in the heavens knoweth her appointed 

 times,' that is true, but how she knows them is a 

 mystery. Let you, Shan, play some part in solv- 

 ing it! 



*' Moreover," he continued, after a pause, **the 

 matter is even more difficult than that. It is 

 extraordinary that birds should follow the same 

 routes in the uncharted sky, with such marvelous 

 exactitude that the Purple Martin coming back 

 from his winter in Brazil mil fly back to the same 

 box in our garden to which he bade good-by the 

 year before. Yet it is even more extraordinary 

 that the same species of bird should have a differ- 



