1916] Chandler: Structure of Feathers 293 



is positive evidence favoring this theory in the ostriches and rheas, 

 as already shown, and the evident close relationship of the latter 

 birds to those of the present group is a strong argument in favor 

 of the Casuariiformes not having had flying ancestors. 



d) Summary 



The Casuariiformes have the following characters in addition 

 to those common to the ratites : 



(1) Remiges greatly reduced, functionless in Dromaeidae, their 

 calami developed into a few stout spines in Casuariidae ; 



(2) Texture of plumage coarse and hairlike, due to long, narrow 

 feathers which have more or less of terminal portion composed ot 

 a coarse shaft and rami with no barbules ; 



(3) Aftershaft similar to main feather plate in both size and 

 structure ; 



(4) Barbules of downy type, practically invariable on different 

 parts of the body, the bases narrow and flattened, the pennula 

 long and filamentous, with prongs sometimes developed at the nodes 

 in Dromaeus, none whatever in Casuarius. 



4. Order APTERYGIFORMES 

 PI. 14, Fig. 5 



This group, comprising several species of a single genus, is 

 probably the nearest to the carinate stem of all the ratite birds. 

 Their general epiphyological characters are as follows: (1) the 

 presence of small lateral apteria, as well as a ventral one (Parker 

 1891); (2) absence of differentiated plumules and filoplumes; (3) 

 remiges and rectrices rudimentary and functionless; (4) aftershaft 

 entirely absent; and (5) no pennaceous structure present. 



The minute structure of the feathers comes nearer to the down 

 of the carinate birds than it does in any other ratite birds. No 

 specialized remiges are present and all the feathers are very similar. 



a) Apteryx haasti 

 (1) Body Feathers 



Shaft and calamus both slender, the former with no discernible 

 ventral groove, and tapering evenly for greater part of its length, 

 widening out a little terminally to produce a stiff, coarse tip. 



