Though the red grouse does not, after the manner of other members of the genus _Lagopus_, become white in winter, Scotland possesses a species of the genus which does. This is the ptarmigan, _L. mutus_ or _L. alpinus_, which differs far more in structure, station and habits from the red grouse than that does from the willow-grouse, and in Scotland is far less abundant, haunting only the highest and most barren mountains. It is said to have formerly inhabited both Wales and England, but there is no evidence of its appearance in Ireland. On the continent of Europe it is found most numerously in Norway, but at an elevation far above the growth of trees, and it occurs on the Pyrenees and on the Alps. It also inhabits northern Russia. In North America, Greenland and Iceland it is represented by a very nearly allied form--so much so indeed that it is only at certain seasons that the slight difference between them can be detected. This form is the _L. rupestris_ of authors, and it would appear to be found also in Siberia (_Ibis_, 1879, p. 148). Spitzbergen is inhabited by a large form which has received recognition as _L. hemileucurus_, and the northern end of the chain of the Rocky Mountains is tenanted by a very distinct species, the smallest and perhaps the most beautiful of the genus, _L. leucurus_, which has all the feathers of the tail white. [Illustration: Ptarmigan.] [Illustration: Blackcock.] The bird, however, to which the name of grouse in all strictness belongs is probably the _Tetrao tetrix_ of Linnaeus--the blackcock and greyhen, as the sexes are respectively called. It is distributed over most of the heath-country of England, except in East Anglia, where attempts to introduce it have been only partially successful. It also occurs in North Wales and very generally throughout Scotland, though not in Orkney, Shetland or the Outer Hebrides, nor in Ireland. On the continent of Europe it has a very wide range, and it extends into Siberia. In Georgia its place is taken by a distinct species, on which a Polish naturalist (_Proc. Zool. Society_, 1875, p. 267) has conferred the name of _T. mlokosiewiczi_. Both these birds have much in common with their larger congener the capercally and its eastern representative.