 These novel conclusions were first presented in the Muséum lectures of 1800, and then were developed in more detail in print in his Recherches sur l’organisation des corps organisés (1802), with the full exposition in his Philosophie zoologique (1809). His theoretical conclusions were also concretely displayed in the arrangement of specimens in the main zoology gallery of the Muséum over which he had primary control. Some further significant elaborations of his ideas were then expressed in his many articles for the second edition of Joseph Virey’s Nouveau dictionnaire d’histoire naturelle (extracted in Lamarck 1817–19 [1991]), and in the long introductory discourse to his major work of taxonomic revision of the invertebrates, the Histoire naturelle des animaux sans vertèbres (1815–22). The following claims formed the core of his mature theory: