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 Casuarwus. 
4. Order APTERYGIFORMES 
Pl. 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. 
