He also took a prominent share in the business of the Museum, in the exchange and in the purchase of specimens and collections in his department, and even in the management of the menagerie.

Thus he reported on the dentition of the young lions (one dying from teething), on the illness and recovery of one of the elephants, on the generations of goats and kids in the park; also on a small-sized bull born of a small cow covered by a Scottish bull, the young animal having, as he states, all the characters of the original.
For one year (1794) he was secretary of the Board of Professors of the Museum.[43] The records of the meetings from 4 vendemiaire, l'an III., until 4 vendemiaire, l'an IV., are each written in his bold, legible handwriting or signed by him.

He signed his name _Lamarck_, this period being that of the first republic.

Afterwards, in the records, his name is written _De Lamarck_.

He was succeeded by E.Geoffroy St.Hilaire, who signed himself plain _Geoffroy_.
In 1802 he acted as treasurer of the Assembly, and again for a period of six years, until and including 1811, when he resigned, the reason given being: "Il s'occupe depuis six ans et que ses travaux et son age lui rendent penibles." Lamarck was extremely regular in his attendance at these meetings.