676 Letters, Extracts, Notices, 6,'c. 
said that when first caught it was coloured like anv other 
Song-Thrush, but had become darker at each moult during 
the later years of its captivity. 
Now, in my experience (and I have kept many examples 
of both) an English Song-Thrush_, even in captivity, is not 
by any means such a long-lived bird as the common Black- 
bird : therefore for oue to live to the astonishing age of 
sixteen years is ver}^ exceptional*. 
Is melanochroism in old age the result of unusual con- 
stitutional vigour^ as leucochroism seems to be of constitu- 
tional weakness ? There is no doubt that white and pied 
varieties of birds are the result either of in -breeding or of 
failing strength : they undoubtedly become accentuated with 
age, as I have noted in the case of all which I have possessed 
(at various times), and notabh^ in the case of a Crimson- 
eared Waxbill [Estrilda phmnicotis) which I have had for 
six or seven years, and which at the present tinle has the 
greater part of its flight-feathers white. 
The abnormal variety of P. gouldice described above will 
be presented to the Natural History Museum. It has been 
fed upon white millet^ spray-millet, and canary-seed ; there- 
fore the change of colour is not due to unnatural feeding. 
Yours &c., 
Arthur G. Butler, Ph.D., F.L.S., F.Z.S. 
124 Beckenliam Rod, 
Beckenham. 
28tji Jiilv, 1902. 
Sirs, — In the ^ lb s' for July, when treating of the birds 
collected by Mr. B. M. Hawker on the White Nile, 
Mr. Ogilvie-Grant remarked (pp. 462-463) on two male 
Ruffs in a peculiar state of plumage. The peculiarity 
consisted in their heads and necks being more or less com- 
pletely white. I think that it may be worth mentioning 
that in the south of Spain, where in certain winters Rufi^s 
are fairly numerous, I have frequently noticed this phase of 
plumage, exactly as described by Mr. Grant in birds from 
* I consider seven years in captivit}' a very good age for a Blackbird^ 
this is probably twice as long as it ^vould live iu freedom. 
