_M. cinereocephala_, which has not yet been obtained in England, but breeds in South Europe from Italy eastwards, may be recognised from _M. borealis_ by its rather darker head and cheeks and by having the _entire throat_ white. Lastly, we have the Black-headed Wagtail, _M. melanocephala_, which inhabits South-eastern Europe and has a black head with hardly any trace of an eye stripe, and which was also obtained on the south coast in 1906. In this form the cheeks and under parts, including the chin, are bright yellow. THE YELLOW WAGTAIL Motacilla raii (Bonaparte) In the flat meadow-lands and pastures intersected by ditches or bordering some sluggish river, we may see this brilliant little fellow as he struts about under the feet of the cattle. At one moment he is running forward to pick some insect off the grass with an audible snap of his slender bill, and the next jumping up to seize, after the manner of the Flycatcher, some winged insect that has come within range of his sharp eyes. This bird is a true migrant, reaching our shores during the latter half of April and leaving us again in September. The males arrive, as is the case with so many species, a few days before the hens, and on their arrival nest-building is begun without further delay. The site chosen is on the ground in the middle of an open field and generally near some upturned sod or in the deep footprints of the cattle. A few grass stems loosely laid together and lined with horsehair suffices for a nest, and the eggs, five to six in number, are of a pale clay-brown with no spots or markings. The birds are very shy when at the nest, leaving it long before the intruder has approached, and only running on again when he is well away. The young are fed exclusively on insects, and when they are fledged remain in their summer home till shorter days and colder nights warn them that autumn has come. Old and young then collect in enormous numbers in the salt marshes along the sea-shore, until with favourable weather they pass on to warmer and more congenial climes. The male above is of a uniform bright greenish yellow, with a yellow eye stripe; under parts bright lemon yellow. Females and young are similar but duller, the latter sometimes showing in autumn some dark spots on the breast. Length 6·25 in.; wing 3·15 in. This bird is distributed in suitable localities throughout England, with the exception of the extreme south-west. In Wales it is chiefly seen on migration, and in Ireland it is only found nesting in a few places. In Scotland it does not nest north of Perthshire, and to the north of the Great Glen it is only a rare straggler. Abroad it is confined to North-west France and the Iberian peninsula, wandering in winter to West Africa. THE TREE PIPIT Anthus trivialis (Linnæus)