422 
Letters , Announcements , fyc. 
In the ( Memoirs of Stephen Grellet* (London, 1860) the follow¬ 
ing entry appears (vol. i. p. 459) under the date of June 1819 :— 
“ Our road led us afterwards frequently in sight of the Putrid 
Sea. We met several herds of Camels, flocks of large birds, and 
some large Eagles. Wolves are very common on these steppes, 
and they are so bold that they sometimes attack travellers. We 
passed by a large one lying on the ground with an Eagle, which 
had probably attacked him, by his side : its talons were nearly 
buried in his back; in the struggle both had died.” 
With reference to the question as to the supposed occurrence 
in India of Milvus affmis, I may mention, as one distinction 
between that species and the smaller individuals of M. govinda, 
that, so far as I have observed, there is no appreciable difference 
between the old and young bird in the former, whilst in the 
latter it is very strongly marked, as it is also in M. melanotis, if 
we may follow Mr. Blyth in considering this a distinct race. 
As to the example of M. migrans from Northern China, which 
is in the Gardens of the Zoological Society, and which Mr. Blyth 
supposes [vide note to p. 248) to be wrongly labelled, I can 
state positively that such is not the case, for I examined the 
bird very shortly after its arrival from China, and have kept my 
eye upon it ever since. It is the only Chinese specimen of M. 
migrans with which I have ever met; but I have seen another 
example which was procured as far eastward as Afghanistan. 
As Mr. Blyth alludes to the colour of the eye in this species, I 
may mention that it varies from pale straw-yellow to dark hazel- 
brown—a fact of which I was not aware when I wrote a note on 
the subject, which was inserted in f The Ibis ’ for 1859 (p. 207). 
All the examples of M. migrans which I have seen with yellow 
irides have been adult birds; but I have seen both young and 
old with brown irides, though paler in the adult than in the 
immature birds. Whether this difference is sexual, as in the 
Harriers, or simply casual, as in the Common Buzzard and 
Golden Eagle, I cannot say, but I think there can be no doubt 
that, notwithstanding these exceptional cases, the colour of the 
iris is a most important guide in the true grouping of the birds 
of prey, and I fully assent to Mr. Blyth’s remarks on this point 
with reference to the Owls in p. 252. 
/ 
