Abstract

in English appeared in these pages (1925). This reviewed the available data resulting both from observational studies and from marking ; it also discussed at length various theoretical questions which consideration of the facts suggested. It is not the purpose of the present paper to traverse all the ground thus covered by Schenk, but only to present a fuller account of the data derived from the marking method which relate to the British Isles. Schenk's paper, in its original form, gave a list of most of the marking records for the Woodcock then available, "but dealt chiefly with the interest of the individual cases which showed considerable movement ; a comprehensive review of all the data Irom this source,of which data from the British Isles form much the larger pari, was thus still required. In the case of the Woodcock there are not only the records obtained by the " British Birds" and former Aberdeen University marking schemes, but many records from private marking schemes which the owners of various estates have undertaken. Two of these schemes have contributed important series of records, and, as these have fortunately been published in detail, summaries of the results are included below. The other private schemes have either produced fewer records, or these have not been fully published; no attempt is made here to deal with most of