Hares, according to the altitude of their range, show almost every degree of variableness between red and white. Our common hare is widely distributed, and to such an extent do varietal forms differ that several distinct species (so called) have been evolved out of one. The extreme forms do seem widely separated, until we connect them with the many intermediate links. It then becomes evident that these differences are, after all, such as may be accounted for by conditions of climate and geographical range. The northern form has thick fur, which inclines to white in winter; the central variety has fur of only moderate thickness, becoming grey in winter; and the southern, thin fur of a deep rufous tinge. The calling of these varieties "species" is simply scientific hair-splitting; though this hardly applies to the true variable or mountain hare. This Alpine form is distributed over the countries within the Arctic Circle, though with us its southern haunt is determined by Scotland and Ireland. Again in this species we have three forms, each mainly characteristic of certain latitudes. The first inhabits warm low-lying countries, and does not change colour in winter; of this the Irish hare is a type. The second, the variety common to Northern Europe, which is grey in summer and purely white in winter; while the third is the Arctic form--white right through the year. The six types are probably all varieties of one species, which, for protection, conform to their own environment; and so successfully do they do this, that the progeny of two pair of mountain hares which in 1854 were turned down in the Faroes might long ago have been counted by thousands. The Scotch variety of this species, which does not change the colour of its fur in winter, is there called the blue hare. Another interesting example of creatures which are brown in summer and white in winter is the ermine. This is still a fairly common British fur animal, and the change may therefore be watched without going far afield. In the fur countries of high latitudes the change is universal; while here, except in unusually severe winters, it is only partial. In the Lake District, where we have observed a considerable number of these animals, a purely white one is exceedingly rare, though pied specimens are not at all uncommon. The nearest general approach to whiteness was during the prolonged severity of the winter of 1880-81. The last colour about to vanish is usually a brown stripe, prolonged posteriorly down the back; though when the weather is of extreme severity the whole transition can be brought about within a fortnight. It is not that the summer fur is cast and a new one substituted for it, but that each individual hair changes colour. Cold artificially applied will in time bring about the same results as a naturally severe temperature.