Containing record of observations at Radley, Blenheim and other locations, and of swifts nesting in boxes at University Museum, Oxford.

Contains observations at Radley and of nesting boxes.

Contains observations of nesting boxes and tabular summaries of data.

Contains record of observations of nesting boxes and of three days at Radley.

Contains record of observations of nesting boxes.

Contains record of observations of nesting boxes and tabular summaries of data.

Contains record of observations in Christ Church meadow, Tring, and other locations. Also contains observations of house martins at Boars Hill.

Field observations by Elizabeth Lack and others at Radley. Observations from Sotwell, Berkshire in another hand.

Notes and observations by Elizabeth Lack on nesting in boxes (includes typescript of 'General summary') published in British Birds, 45, pp.186-215.

'Swift. Ibis. Other people's data': notes on books and articles, statistics and observations on apus apus, correspondence. 'Nesting Success etc.': information and correspondence.

Tables and observations by David and Elizabeth Lack.

Notes and charts, distribution maps, notes on books and articles read, correspondence regarding 'The Species of Apus', Ibis, 98, pp.34-62.