vi PREFACE 



States Department of Agriculture, for permission to 

 reproduce plates from its publications, and to the 

 Museum of Vertebrate Zoology, University of Cali- 

 fornia, for the privilege of reprinting a map by Mr. 

 H. S. Swarth to show the distribution of fox spar- 

 rows. Mr. Gregory Mathews, the well-known au- 

 thority on Australian birds, has read the sections 

 dealing with Australia, and I am indebted to other 

 friends for suggestions. 



Alexander Wetmore 



Washington, D. C. 

 May I, 1926. 



