Notebook recording Bateson and Punnett's experiments with sweet pea crosses. The book contains records for plants sown in February and March 1903.

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.

Some records note problems with mice eating the seeds [e.g. pp 1:17 and 1:18]. The plants on [pp 1:83v-1:84r and 1:92v - 1:93v] are marked ‘important’ and 'v important'; that on [page 1:45v] is marked ‘burnt by mistake’, while the plant on [pp.1:89v-1:90r] is marked ‘peculiar case’. Some records are unusually detailed [e.g. pp 1:126v-1:128, 1:139, 1:142, 1:166v-1:167r, 1:222v-1:223r]. A set of loose pages inserted into the back of the notebook [pp 2:1-2:9] includes lists of plant numbers against plots and rows, and maps of Plots I-V.