PREFACE. 



volume. They are of opinioa that more attention 

 should be devoted to this important branch of 

 Ornithology, and they trust that some of the 

 younger Members of the Union will take up the 

 subject. Even among British birds there is ample 

 material to be found for such investigations. 



P. L. S. 

 H. S. 



September 301 h, 189.^). 



