VI 



FORM AND FUNCTION 



greater girth of the hollow bones in proportion to their 

 length is at once obvious. But to bring this out still 

 more clearly, I have taken the wing bones of the Skua 



Humerus of Pomatorhine Skua (a) ; Rhinoceros Hornbill (b) ; and Vociferous Sea 

 Eagle (c). Drawn to scale. 



as the standard, and calculated what would have been 

 the length of the same bones and of the whole wing in 

 the Sea Eagle and the Hornbill, if they had been built 

 upon the same lines ; 



