Darwin 's most important scientific work is ZoÃ nomia ( 1794 â `` 1796 ) , which contains a system of pathology , and a treatise on generation , in which he anticipated some of Lamarck 's ideas on evolution . Darwin 's most important scientific work is ZoÃ nomia ( 1794 -- 1796 ) , contains a system of pathology , and a chapter on ` Generation ' .