THE ZooLtocist—May, 1875. 4437 
occur which seem to unite it with M. alba, of which it is probably 
a mere race.”—Hancock, p. 62. 
The so-called varieties are probably only immature birds: really 
adult birds of M. Yarrellii have the head, back and rump in- 
tense black in the summer and winter, while M. alba has the 
head only black, and the back and rump pure light gray. 
Mr. Hancock says of our yellow wagtail that it probably should be 
considered a “race” of the grayheaded wagtail(p.61). The two birds 
exhibit constant differences, which are very striking when they are 
adult. They have never, I believe, been known to breed together, 
and if they are not distinct species, 1 do not know what constitutes 
a species. 
Red Grouse (Lagopus scoticus, Brisson).—“ This fine resident 
species is found wherever heather and ling abound. It is generally 
considered to be peculiar to the British Islands. It comes, however, 
so close to L. Saliceti or albus, that the two so-called species can 
scarcely, in the summer dress, be distinguished ; in size they agree, 
and in the colour and markings of the plumage they are the same.” — 
Hancock, p. 88. 
I differ entirely from Mr. Hancock in his views regarding these 
birds. I believe they are distinct species. Temminck states that 
L. scoticus has sixteen feathers in the tail and L. Saliceti eighteen: 
Ihave no means at the present time of ascertaining the correctness 
of this statement. The beak of L. Saliceti is certainly much stronger 
than that of L. scoticus. The lower part of the breast, the belly 
and quill-feathers of the wings are pure white at all seasons of the 
year ; yet Mr. Hancock states that the two species can scarcely 
be distinguished in their summer plumage. ‘The quill-feathers of 
L. scoticus are blackish brown. The one mentioned by Mr. Han- 
cock as having them white was evidently merely an accidental 
variety. 
The ptarmigan undergoes the same seasonal changes of plumage 
in Scotland as it does in the North of Europe, and it is very 
remarkable that the red grouse should not undergo the same 
changes if it is a mere variety of the willow grouse, which 
invariably becomes pure white in the winter. 
M. Temminck says, in the second edition of his ‘Manual’:— 
“TY made a great mistake in my first edition respecting that very 
distinct species the Tetrao scoticus of Latham, which I regarded as 
my Tetrao Saliceti in summer plumage, a species which is subject 
SECOND SERIES—VOL, X. Zi 
