ORIGIN AND CHARACTERISTICS 41 



fulfilled. It is interesting to remark that a similar 

 " egg tooth " is present in reptiles and used for 

 the same purpose. We might say with perfect 

 truth that the modifications in the form of the 

 bill are almost endless adapted for every con- 

 ceivable method of obtaining food. A brief 

 glance at some of the most striking types must 

 however suffice. Passing over the ordinary type 

 of bill which is found in such a large number 

 of birds even belonging to the most diverse 

 families, we have as specially modified forms the 

 broad, depressed, lamellae-furnished bills of the 

 Duck tribe ; the powerful curved and hooked 

 bill of Raptorial birds ; the exceptionally strong 

 and rounded bill of the Parrots, so admirably 

 adapted for reducing to pulp the hard nuts and 

 fruits upon which these birds so largely subsist ; 

 the chisel or wedge-shaped bill of the Wood- 

 peckers, which enables those birds to reach their 

 prey or excavate their nest holes amongst timber. 

 Then we may instance the lance-shaped bills of 

 the Herons and Divers, adapted to seize fishes, 

 or the broad, flat spatulate bill of the Spoonbills. 

 Or, again, as quite another type, the singularly 

 weak bill of the Swallows, Goatsuckers, and 

 Swifts, almost functionless as a food seizer. The 

 amount of variability in the form of the bill in 



