1916] 



Chandler: Structure of Feathers 



391 



\Cypselidae\ | Pa sseriforrnes\ 



I Pici I J^Coraciae\ 



Fig. G. Phylogenetic tree showing hypothetical relationships of birds, based 

 on Knowlton and Ridgway's (1909) classification, with all changes 

 suggested by morphology of feathers incorporated. 



