THE STORY OF THE CASSOWARIES WING. 



In the young bird the degenerate flight feathers have a typical barrel, or quill, 

 and feebly developed shaft and "vane," as in the left-hand figures in the inset. 

 I^ater, the shaft and vane sloughs off, and the hollow quill becomes solid, as in the 

 large upper figure. The small wing is that of the Apteryx, in which the shaft and 

 vane are retained through life. 



3. "14] 



