Mr. White distinguished no fewer than three varieties of the Willow Wren. “I have now,” he writes, “past dispute, made out three distinct species of the Willow Wrens, which constantly and invariably use distinct notes.” “I have specimens of the three sorts now lying before me, and can discern that there are three gradations of sizes, and that the least has black legs, and the other two, flesh-coloured ones. The yellowest bird is considerably the largest, and has its quill feathers and secondary feathers tipped with white, which the others have not. The last haunts only the tops of trees and high beechen woods, and makes a sibilous grasshopper-like noise, now and then, at short intervals, shivering a little with its wings when it sings.” Mr. Markwich, however, declared that he was totally unable to discover more than one species. [Illustration: THE GOLDEN-CRESTED WREN, (_Regulus cristatus_,)] IS the smallest of British birds, measuring only three inches and a half in length. It is of an olive colour, with a beautiful crest of golden yellow feathers on its head. This charming little bird is generally found in fir woods; it feeds on insects, and has a soft and pleasing song. [Illustration: THE GREY WATER WAGTAIL. (_Motacilla boarula._)] THERE is not a brook purling along two flowery banks, not a rivulet winding through the green meadow, which is not frequented by this beautifully coloured and elegantly shaped little creature. We even see them in the streets of country towns, following with quick pace the half-drowned fly or moth, which the road-side streamlet carries away. Next to the robin redbreast and the sparrow, they are the boldest in approaching our habitations. The Wagtails are much in motion; seldom perch, and perpetually flirt their long and slender tails, (whence they derive their name,) principally after picking up some food from the ground, as if that tail were a kind of lever, or counterpoise, used to balance the body on the legs. They are observed to frequent, more commonly, those streams where women come to wash their linen; probably not ignorant that the soap, the froth of which floats upon the water, attracts those insects which are most acceptable to them. [Illustration: PIED WAGTAILS.] THERE are two common species of Wagtails, the Grey kind and the Pied Wagtail. The Grey Wagtail is retiring in its habits, and much slower in its motions; its breast is yellow, and its wings grayish, but the Pied Wagtail, which is a very lively little bird, and seems always in a bustle, is black, softening into ash-colour and white; it is also bold, and will take the food thrown to it with as much confidence as a robin redbreast.