3i FORM AND HABIT: THE BILL. 



that of tlie female is long and curved. The birds feed 

 on larvre, which thej lind in dead wood. The male 

 hammers and chisels away the wood very much as Wood- 

 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. 



