TO RESEMBLE OTHER SPECIES. 
241 
former class are the Grey Crows, Goldfinches, and Grey Shrikes, and 
of the latter the Blackgrouse and Greenfinch. The old naturalists 
had no idea of the extent of crossbreeding, though it went on 
under their eyes ; some of them almost scouted its possibility. 
But the labours of M. Andre Suchetet have shown how common 
hybridism is, he having collected enough instances to make a bulky 
volume of S73 pages, though at the end expressing doubt about 
some of them. 
The following twenty cases will perhaps bear either the 
interpretation of abnormal resemblance or hybridism, as the reader 
elects to view them; but I prefer to see “resemblance” in them, 
(except in No. 9 and No. 11) as the easier reading of the riddle of 
mixed plumage : — 
No. 1. On three occasions adult males of our British Sparrow 
Hawk, Accipiter nisus, have been shot in this country, which so 
far resembled the South African A. rujioentris, Smith, as to have 
the breast and underparts a clear rufous without any transverse 
bands (rf. ‘ Ibis,’ 1893, p. 340), as may be seen from the picture of 
one of them in Hancock’s ‘ Birds of Northumberland.’ To what- 
ever cause it may bo due, the coincidence of colour is very marked, 
the birds being adult, and their red appearance could hardly fail 
to attract the notice of any one conversant with British Birds. 
No. 2. In the same way the Peregrine Falcon will sometimes be 
uncommonly like the Lanner, Falco feldeggii, especially about the 
head. 
No. 3. In 1875 I shot in Egypt a Lanner Falcon, Falco feldeggii, 
almost as dark as the South African F. tanypterus , which had 
actually paired with another F. feldeggii of the normal type, yet 
these two species are kept apart bv all the best naturalists. 
No. 4. Buzzards which were indistinguishable from the rufous 
North African Buzzard, Dttfeo deserturum, have been killed in 
England three or four times (cf ‘Ibis,’ 1889, p. 574), and unless 
we admit the theory of resemblance here advanced, this distinct 
species is entitled to admission to the British list, though never 
enrolled. No one for an instant doubts the distinctiveness in these 
days of Buteo vulgaris and B. desert or am which inhabit a different 
geographical area.* 
* Several fine examples of Accipiter rufiventris, Falco feldeggii, 
F. tanypterus, and Buteo desertorum, on view in the Norwich Museum, are 
available for comparison. 
