206 Animal Life 
(Carduelis carduelis and ©. caniceps) encounter each other; and where the Blue 
Rollers of India and Burma (Coracias indicus and C. affinis) come into contact, to 
say nothing of many other cases. 
It is a question, however, whether this can be called true hybridism, since it may 
reasonably be argued that species which have got no further in separation than a 
different plumage are not as yet fully distinct, but rather comparable to the colour- 
varieties in our domesticated birds. That the intermediate birds represent the ancestors 
of the two forms does not seem at all probable, because the evidence is in favour of 
colour-varieties appearing suddenly, and not by gradations from an intermediate type. 
Thus, there are two forms of the common Peacock, the typical Pavo cristatus and 
the black-winged Pavo nigripennis, but there has never been an intermediate ancestor 
to these, for we know for a fact that the black-winged form, like the albino one, arises 
quite suddenly from the ordinary bird. It may also be remarked that the free 
interbreeding of forms or species separated only by colour is a fatal blow to the 
common theory that colour-differences are “recognition-marks” by which birds of a 
feather are enabled to flock together. 
The fertility of undoubted hybrids—between species where other points combine 
with colour to make a distinction admitted by everyone—is still very 
widely disbelieved. And there is some reason for the disbelief, 
since it appears to be the case that the commonest bird-hybrids, 
the “mules” between various British Finches and the 
Canary, are usually barren, though they will pair, 
lay, and sit in the most exemplary way, a hen 
“mule” being a notoriously good nurse 
for young canaries. Another common 
hybrid, that between the Fowl = 
and Pheasant, is also well v 
known to be sterile, as likewise 
are those between very distinct 
genera of pheasants. | Nevertheless, 
fertile hybrids have been so often 
recorded in some cases that there is no 
possible doubt about them. A good typical 
instance is that of the hybrid between the 
Gold - Pheasant and Lady Ambherst’s Pheasant E (Chrysolophus pictus and 
C. Amhersti@). The details of plumage in these birds are quite different, apart from 
the very different coloration of gold and scarlet in the one and dark green and white 
in the other. The Amherst has a much larger tail, but a smaller crest, which grows 
only from the back of the head; his ruff is also fuller, and the feathers composing 1 
are rounded instead of squared at the tips. The hens, also, though much alike at the 
first glance, can easily be told apart, the Amherst hen being bigger with a smaller 
head, and having a bare livid patch round the eye, and lead-coloured legs, while the 
gold-pheasant hen has dull yellow legs and the face feathered over. 
Now the hybrids between these two very distinct birds are fertile every way, 
either between themselves or with the parent stocks. Indeed, when Amherst hens 
were scarce, which was the case for some time after the introduction of the species, 
it was a common practice to pair Amherst cocks with golden hens, and breed the 
hybrid hens with the Amherst again, till the strain became practically pure Amherst. 
The hybrid cock is a more beautiful bird than either pure species, combining the 
scarlet of the golden pheasant with the larger amount of deep green of the Amherst, 
and possessing a crest as full as that of the golden pheasant but of a flaming 
Photo by 
W. P. Dando. 
HYBRID PHEASANT 
(Amherst and Golden). 
