The gold-crest is our smallest British bird. The ranks of our resident "gold-crests," in the autumn, are swollen by immigrants from northern Europe, who seek shelter with us because unable to withstand the rigours of the more northern winter. In the matter of size the gold, and fire-crested wrens agree, measuring but a trifle more than three and a half inches from the tip of the beak to the tip of the tail! By the way, the shape of the beak should be carefully noted. It is that of a typical warbler. It may be urged that this description of the warblers might well have been omitted from these pages, since, in regard to "Flight," nothing whatever can be said, save that they "fly." There would indeed, be some justification for such criticism, but it is to be remembered that this volume is written, not for the expert, but for the novice, who, because he needs a few concrete examples of the hopelessness of expecting to identify every bird he may encounter by its flight, and of the methods he must occasionally adopt, when seeking to name a bird which will not come out into the open. His course of training, and discovery, will be much shortened by the realization that birds by no means always reveal their presence by taking long flights. What is true of the warblers, in this regard, is true also of our numerous species of tit-mice. We do not distinguish between them in the field by their flight, but by their coloration. But since these are such confiding little birds, coming to our very windows during the winter months, for food, a few notes concerning them may be acceptable. The commonest of all is the little blue-tit, or "tom-tit," as it is so often called. Its beautiful cobalt-blue crown, blue back, wings, and tail, white face, and yellow breast, are familiar to us all. Its larger relative, the great tit-mouse--the largest British tit-mouse--bears a close general resemblance to the smaller species, but is readily distinguished, not only by its greater size, but by the broad band of black running down the abdomen. Its flight, as of all the tit-mice, is weak, and as it were, uncertain, confined to short passages from tree to tree. The coal tit-mouse and the marsh tit-mouse are seldom recognized as distinct species, by the novice. They are very soberly coloured little birds, the coal-tit being of an olive-grey, tinged with olive-buff, while the sides of the body are buff: the head and throat are black, relieved by a broad patch of white on each side and down the nape of the neck. The marsh-tit is, to all intents and purposes, of the same coloration, but differs conspicuously in lacking the white patches. The tiny longtailed-titmouse cannot possibly be mistaken for any other bird. Its delicate hues of pink and grey, and extremely long tail, make comparisons with any other species unnecessary.