BRITISH WARBLERS
lands, especially, in the latter countries, along the banks of the Rivers Scheldt and Meuse. I did not find it as common as I should have expected in the Island of Texel: it passes over Heligoland in great numbers.
Continuing northwards, we find it generally distributed throughout Denmark and breeding in suitable localities. In the south of Sweden it is common, then becomes rarer as far as the south of Norrland, but north of this it apparently does not occur: it is unknown in Gothland. In the south of Norway it is rare, but has been observed in the Jäderen district and up to Laurgaard; north of this it disappears until we reach Dynnäsö in the Helgeland district, where it becomes more common again and reaches as far north as Finmark.
Returning to Central Europe, we find it generally distributed over Germany and especially common in the marshy parts of Mecklenburg. Holstein and Westphalia; also in Hessen and along the banks of the Rivers Moselle and Elbe; rare, however, in Sachsen-Altenburg, but very common in Silesia. In Switzerland it is fairly numerous, especially in the low-lying country and valleys round Geneva and Lake Constance, but in the central and northern parts it is rarer, although inhabiting some of the lower sub-alpine valleys, especially Hasli. In Italy it is common in all the marshy parts, but not so numerous in Sardinia, and rare in Corsica. Eastwards, we find it again common in the Austro-Hungarian Monarchy, especially in the central plains along the banks of the Danube. Whether it breeds in Montenegro is doubtful, but immense numbers pass on migration. On the east side of the Balkan Peninsula we find it common in the reed-beds of Varna and Pravadia in Bulgaria, but further inland less numerous.
In Greece it is a bird of passage only, appearing on migration in large numbers from the end of March to the end of May. It may, however, have been overlooked as a
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