WoBURN Abbey, 



2ist July, 1902. 



It is not every one who has the taste, capacity, or 

 leisure for the scientific study of Natural History. But 

 there are few persons who do not feel that some know- 

 ledge of the processes and products of Nature increases 

 the enjoyment of country life. To supply this knowledge, 

 in a form at once easily assimilated and scientifically 

 accurate, is the object of the Woburn Series of 

 Natural History. 



Each subject will be treated by a writer who has 

 made it his special study. In this volume, therefore, 

 as in all the succeeding volumes, the writer speaks for 

 himself, and the Editor has not attempted to impose 

 his own opinions on those who have been asked to 

 contribute to the series. 



