This is the first of six poultry ledgers which were kept alongside Bateson and Punnett's laboratory notebooks for poultry breeding. Entries are in ink in small neat handwriting in contrast to the poultry notebooks where entries are in pencil and sometimes difficult to read.

The ledger contains records of individual hens organised by pen, with records of eggs laid and number and sex of chicks. The years covered are 1904 [pp. 1-32], 1905 [pp. 33v-81], 1906 [pp. 82v-117], 1907 [pp. 119-145], 1908 [pp. 147-168], 1909 [pp. 170-191], and 1910 [pp. 194-212]. It includes a lists of male and female chicks for 1904-1906 [pp.114-117], a list of pens where pure Brown Leghorns were used [page 209v], pedigrees for Brown Leghorn and R. White breeds [pp.210-211], and a list titled 'Sex distribution of E.T. in certain experiments' [page 212].