168 MR. W. P. PYCRAFT ON THE MORPHOLOGY AND 
In the Dinornithide the rami and radii are short. The latter, from the middle of 
the feather to its base, are filiform and divided into a series of numerous short joints, 
the anterior ends of which are produced into two or three pointed fila. Thus these 
radii most nearly approach those of Apteryx, but they may be at once distinguished 
therefrom by the relatively great length of the fila. 
The distal ends of the rami bear no radii. 
The feathers of Dinornis were first described by Dallas [15]. His description is 
appended below :— 
“The structure of the web is somewhat different from that which occurs in the Emu 
and the Cassowary. ‘Towards the base of the shaft the barbs spring in groups of four 
or five together from nearly the same spot, and thus this part of the web assumes a 
tufted aspect. As we advance towards the apex this arrangement speedily ceases; the 
number of barbs springing from the shaft gradually diminishes until each side bears 
only a single series of these appendages. The barbs consist of slender, flattened fibres, 
bearing long, silky, and very delicate barbules, without any trace of barbicels, and 
presenting a distinctly beaded appearance when examined by a simple lens. Under 
the microscope..... the barbule appears merely divided by faint transverse partitions 
into a series of cells, some of which towards the apex exhibit small tooth-like projections 
representing rudiments of barbicels.... . The barbs nearest the base of the feather, 
both in the main web and accesscry plume, are destitute of barbules for some distance 
from their base; but this distance gradually decreases until the barb is furnished with 
barbules throughout its whole length.” 
As Dallas remarks, these fragments still leave us in ignorance of many points, 
such as whether the basal rami (barbs) possessed the hair-like tips of the Emu and 
Cassowary, and whether the apical portion of the feather supported simple rami as 
in these last. 
SUMMARY OF PTERYLOLOGICAL CHARACTERS, 
Perhaps the most interesting pterylological result of the present enquiry has been 
the light thrown upon the history of the remarkable wing-spines or vestigial remiges 
of Casuarius. The comparison of these with the remiges of the nestling on the one 
hand, and with the wing of Apterya on the other. leaves little or no doubt but that 
the explanation, or rather interpretation, of the nature of these degenerate feathers is 
correct. 
The form and disposition of the apteria have been described at greater length than 
ever before, and some new facts added. The existence of apteria has long been known— 
at least in Struthio and Apteryx; though these facts had not yet found their way into 
the text-books, which still repeat the old error that the feathers of the Palwognathe 
were evenly distributed over the body, 
The form and structure of the nestling-down has been worked out in considerable 
