Notebook recording Bateson and Punnett's experiments with sweet pea crosses in 1910 and 1911. A note on the fly leaf in Bateson's handwriting states that 'all plants which were saved for seed at Merton died from ?eel-worm' [page i].

The notebook begins with 1910 records, paginated 1-68 (of which pp 36-38 are blank). The numbering sequence then begins again, running 1-90, for the 1911 records [page iii] (of which pp 49-50 and 82-90 are blank), followed by three excised pages. The rest of the notebook is blank except for a set of notes at the back giving details of crosses and maps of the layout of the plant beds [pp iv-viii].

The general format of the record is that the parents are recorded as numbers with a superscript or sometimes as a named variety. Since sweet peas can be selfed, some crosses have only a single parent. The date of sowing and the date of planting out are recorded, together with other observations on the plants such as colour, height and petal form. The plants on [pp 2:29v-2:32] are marked as a 'new combination' requiring special care.