Notebook recording Bateson and Punnett's experiments with sweet pea crosses in 1908.

Records were paginated 1-46, followed by a set of blank pages; pagination then continues from 59-167 followed by a longer series of blanks. At the back of the notebook is a set of maps of the layout of the plant beds [pp iii(v)-vi]. Entries are recorded in two different handwritings.

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.

A note has been inserted into the book [page 79a] containing details of a cross they were clearly looking for: a 3:1:1:3 Mendelian segregation. From this point on the scoring and classification of progeny becomes much more detailed and systematic, and tables of classified progeny begin to appear [e.g. pp 162v-167].