Two letters to Bateson from G.H. Shull, Station for Experimental Evolution, Carnegie Institution of Washington, USA, relating to 'twin-hybrids' of Phaseolus. Included are manuscript notes and data.

Contents of four envelopes which are listed separately below. Inscriptions on the envelopes are reproduced. The box in which the envelopes were found contained the following note on a piece of paper: 'Broad Bean variegation to sowing of June 1925'. This piece of paper has been included in B.8.

8pp typescript draft with manuscript revision; further typescript draft; revised version with copy of Darlington's letter to the publisher.

Correspondence to Bateson from various individuals including R.H. Biffen, E. Baur and E. Gold (Meteorological Office), with several pages of enclosed data and notes. Some letters and pages of notes are in German.