34- FORM AND HABIT: THE BILL. 



that of tlie female is long and curved. Tlie l)irds feed 

 on larvjB, wliicli they find in dead wood. The male 

 hammers and chisels away the wood very much as AVood- 

 peckers do, while the female uses her bill as a probe. 

 We have, therefore, the singular case of two forms of 

 the bill arising in the same species as a result of or caus- 

 ing a corresponding difference in habit. 



