THE BIRDS OF AUSTRALIA. 
environmental stress capable of modifying this bird in this range. In 
measurements it is slightly less than the typical series, but no long series are 
available to discriminate in the region named. The name gymnopis has been 
applied to this form but I have shown that this is inapplicable. We must 
therefore call this race 
Ducorpsius sanguineus ashbyi Mathews. 
I would here comment upon a criticism in the Ibis, 1916, p. 649, upon 
my treatment of the forms of Ieracidea. My friendly critic has thus written, 
“ Of this Hawk innumerable variations seem to occur ; and, as they overlap 
in places, we should ourselves have refrained from accepting, or giving, Latin 
appellations to each, while considering them somewhat erratic manifestations 
of an extremely variable species, or phases not yet sufficiently fixed to warrant 
nomenclatural distinction.” 
I had, however, just proved that the phases were “ not somewhat erratic 
manifestations ” and “ warranted nomenclatural distinction ” to emphasise 
that fact. The designation by a certain name attracts workers and in that 
case we arrive sooner at the truth by contradiction or confirmation, and 
Capt. S. A. White, the most brilliant, experienced and thorough field 
ornithologist in Australia, has just written (Emu, Vol. XVI., July, 1916, p. 12) : 
“ Ieracidea berigora occidentalis. Several birds seen on Wedge Island, 
South Australia. In my opinion this is strictly a coastal form, and Ieracidea 
b. berigora takes its place inland.” I make this interruption as the critic’s 
remarks seem more applicable to the present case, and I therefore forestall them, 
as so far I cannot conclude that the differences observed are only “ somewhat 
erratic manifestations,” though it may be argued that the “ phases are 
not . . . fixed ” ; nevertheless it seems most desirable to indicate the 
presence of these phases, so that their status can be determined, and the only 
method apparent is the proposal or acceptance of names. As will be seen 
from the preceding, I am always ready to discard a name when its use seems 
unnecessary ; and it is certainly the usage of names that express facts ; 
whether the further study of birds will prove that these facts were only 
correct in application to the specimens examined or are true for all speci- 
mens remains to be seen. 
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