Reed Warbler and Marsh Warbler. 



71 



similar, they were not in song, nor did we hear them 

 utter even a call note, so that there was nothing to 

 differentiate them except their size or plumage. But 

 in size they are exactly the same, while even with the 

 two birds side by side in the hand their plumage is so 



THE CAMP AT DUEM. 



similar that no one but an expert would detect the 

 difference. 



It was most interesting to come across birds with 

 which one was familiar in England in their winter 

 resorts or on their migrations so far to the south. The 

 extraordinary power of the migrating impulse was 

 brought vividly home to me by the .presence of a solitary 



