The Argosy — page 311: what you’re looking at

Machine-transcribed from the original scan — historical spelling and the odd misread are preserved.

290 Anmal Disguse and Defence. but even the extent to which the change is carried. In opener seasons the white or lighter hue is less decided ; in severer, more so. There is no casting off of the fur. The colouring pigments are, so to speak, withdrawn. ‘The stoat, in his rich brown summer coat, could hardly be better protected than by it when among the dying erass and bracken and sandy hedge-sides; but that would serve him ill and make him a very clear mark for his enemies on the wide, unbroken expanse of snow. The change operates soonest on the portions most exposed—the sides, the belly, the legs. In open seasons indeed patches are left— usually a straight strip down the back and spots on the head and shoulders—these always diminishing if the cold grows more intense. The tip of the tail is always black. Specimens are found in quite a transition stage. It should be added, too, that the more intense the cold, the fur becomes at once the thicker and glossier. The reason of this is obvious, at once to throw off the light and to preserve in- ternal warmth. In speaking of birds, we did not refer to the most striking instance of the snow-bunting, because its most marked feature is the winter change, of which we will now speak. Here, as in the case of the quadrupeds, the extent of the change is determined by the measure of winter severity ; and evidently, from this fact and other circumstances to be noted immediately, there is present in the bird some prophetic instinct or forecast of weather. In summer the plumage is sufficiently beautiful and distinctive: the head, most part of the breast, and the margins of the feathers above are a tawny orange, mixed here and there with patches of pale grey; and the rest of the upper feathers are brown-black. The change of colour has nothing to do with moulting. First of all, the colour is withdrawn from the tips of the feathers, and this pro- ceeds downwards and downwards till, at length, all that is exposed to the eye when the feathers are unruffled is white; the under plumage remaining as it was, The snow-bunting, often called the “ snowflake,” is a lover of remote hills and dales; and its premature appearance in white plumage or partially white plumage, in the later autumn, often causes no little concern to the hill-farmers in the north, where grain or potatoes may be still exposed ; and if they are wise they now lose no time in getting them in, for experience has taught that the advent of the ““ snowflake,” with his partially-changed plumage, means early and severe winter weather ; and this more especially if the days should then be clear and fine—one of the most deceptive of all things in higher latitudes at that season. In principle, it is precisely the same with the ptarmigan in its change from blue-grey to pure white. With regard to it one of our best naturalists says :— | “Great as is the protection afforded by their assimilation to lichen- Eomichbooks.co