Lamarck published a series of books on invertebrate zoology and paleontology. Of these, ''Philosophie zoologique'', published in 1809, most clearly states Lamarck's theories of evolution. The first volume of ''Histoire naturelle des Animaux sans vertèbres'' was published in 1815, the second in 1822. Aside from Lamarck's contributions to evolutionary theory, his works on invertebrates represent a great advance over existing classifications; he was the first to separate the [[Crustacea]], [[Arachnida]], and [[Annelida]] from the [[Insecta.]] His classification of the mollusks was far in advance of anything proposed previously; Lamarck broke with tradition in removing the tunicates and the barnacles from the Mollusca. He also anticipated the work of Schleiden & Schwann in cell theory in stating that: | Lamarck published a series of books on invertebrate zoology and paleontology. Of these, ''Philosophie zoologique'', published in 1809, most clearly states Lamarck's theories of evolution. The first volume of ''Histoire naturelle des Animaux sans vertèbres'' was published in 1815, the second in 1822. Aside from Lamarck's contributions to evolutionary theory, his works on invertebrates represent a great advance over existing classifications; he was the first to separate the [[Crustacea]], [[Arachnida]], and [[Annelida]] from the [[Insecta.]] His classification of the mollusks was far in advance of anything proposed previously; Lamarck broke with tradition in removing the tunicates and the barnacles from the Mollusca. He also anticipated the work of Schleiden & Schwann in cell theory in stating that: |