The nest, as a rule, is placed near the ground, in a hole in a rotten tree-stump, or in a wall, or any other suitable place. It is composed of moss, hair, and feathers, felted together, and lined with more feathers. Six to eight eggs are laid, like those of the great tit in colour. Like the oxeye, it is omnivorous, but in summer it feeds principally on insects. After the breeding season the old and young birds keep together, and several families may unite and form a flock. One of the most interesting winter sights in a wood composed of pine and fir growing together with beech and other deciduous trees is afforded by a wandering flock of coal-tits. As they move from tree to tree they attract other species of similar habits--the oxeye and blue and marsh tits, and goldcrests, and siskins, and perhaps a couple of tree-creepers. Occasionally a party of long-tailed tits will join, and keep with the flock for some time; but the long-tails are the most restless and vagrant of all, and eventually hurry on by themselves, leaving the more patient plodders behind. It is wonderful and very beautiful to see so many species thus drawn into companionship by a common social instinct, and by a similar manner of seeking their food; a mental likeness serves to keep them together for hours at a time, or for a whole day, in spite of so great a diversity in form and colour and language. Marsh-Titmouse. Parus palustris. Forehead, crown, head, and nape black; upper parts grey; wings dark grey, lighter at the edges; cheeks, throat, and breast dull white. Length, four inches and a half. * * * * *