368 A FIRST LIST OF THE BIRDS 
very home and stronghold of the species. A melanism that 
affects 33 per cent. of the community, surely deserves the appella- 
tion of a stage of plumage. 
That this dark form has not yet been observed in China and 
Japan, and on the other hand is common in the Himalayas is 
entirely in favour of its being the plumage of age and not a 
mere melanism. MHabitually the younger birds extend their 
migrations further than the older ones ; if the black birds are 
old adults, they would, of course, be very rare in China and 
Japan, where the species is only, I believe, a winter migrant, 
from a distant locality, while (as is a fact) they might be ex- 
pected to be common in the Eastern Himalayas which are a 
portion at any rate of the head-quarters of the species. But 
if the dark stage is a mere accidental melanism, independant 
of age, then the observed facts are much less easily explicable, 
indeed become inexplicable. If my contention that the dark 
stage is dependant on ave be rejected, then it seems to me that 
the only tenable alternative hypothesis is that tne dark stage 
represents a local species or sub-species, bearing the same rela- 
tion to japonicus that Cyanocincla solitarius does to C. cyana. 
Under no circumstances does it seem to me that the accidental 
melanism theory sufficiently accounts for the known facts. 
As Mr. Gurney truly observes, the precisely parallel case 
of B. ferox ought to throw some light on the suject. Through- 
out the plains of the North-Western Provinces the dark birds 
are almost, if not wholly, unknown. Further west and north 
in the Punjaub and Rajpootana, these begin to appear, but: still 
throughout the greater portion of these tracts they are rare, 
and the great bulk of the specimens are still, as they almost 
universally are, in the North-Western Provinces in what I call 
the first stage of plumage. Itis only in the extreme north 
and west, in the Punjab, about Peshawur and Murdan, and 
trans-Indus and again in Sindh trans-Indus that the dark form 
is at all common ; and in some few places in the latter locality 
they seem to be more numerous than the white and rufous 
birds. This is in the immediate neighbourhood of the breeding 
places of, as I believe, the majority of the birds that visit the 
plains of India. 
But it will doubtless be said that the birds breed also about 
Sarepta in Palestine and elsewhere, and that no considerable 
number of black birds are ever there obtained. If this is 
correct, then all that can be said is that the Hastern race that 
breeds in Afghanistan and Beloochistan (and possibly Persia also) 
differs in assuming, when old or quite adult, a stage of plumage 
only accidental in the western race ; and such difference is 
quite in harmony with what I have already noticed in regard 
