Laboratory notebook containing records for birds from poultry breeding lines A, B, C, and D (which hatched between circa June and September 1899) and breeders for 1900. These are followed by four pages of abbreviated notes [pp. 113v-116v], and the beginning of records for the first W series (W 1-48; [page 120v]) representing chicks which hatched between February and April 1900.

Entries for each bird include notes on colour, comb and other physical characteristics or oddities (e.g. bulging eyeballs), state of health, and cause of death, etc. Some entries are initiated by Bateson [e.g. page 121]. The entry for bird W 14 records that it was killed by a cat [page 134].